The metal nozzle screwed onto cans is a very good investment. It greatly reduces the amount of foam waste, which pays for itself. Also, the foam release can be adjusted more efficiently and a longer nozzle reaches further.
The foam guns are helpful, but we do not always use them. We find many areas where they are too large and cumbersome to allow us to seal gaps and openings effectively. In these areas the small cans of Great Stuff come in handy. Andy
@@insulwiseenergycomfortsolu3293Interesting reply…based on vids of installers trying to demo different types of foam products, by creating several side-by-side “beads” used for comparison, without any nozzle attachment, those comparison beads were not uniform in depth, thickness or alignment. Kind of a mess without using the nozzle piece. IMHO
Good stuff! If it's in the budget, have the insulation contractor pull all the old insulation at the start of the project. Makes it much easier to find & fix all the air leaks.
Thanks! If possible sure that certainly makes the air sealing easier. But if the team doing the work is used to air sealing when there is insulation down, are mapping the air leaks, and testing out with blower doors you can get the same result, and also save the homeowner a few thousand bucks while doing it. That said, I would not trust most of our local competition here to get the results that we get with the insulation still in place. Properly air sealing an attic floor is tedious, time consuming, methodical work -- and that's when the attic temperatures are "friendly".
I can't thank you enough for this video. Very informative and I wish I knew about this a long time ago. Our house seems to get colder every single winter, despite doing everything right with furnace maintenance, weatherproofing gaps, e.t.c. We've uncovered so many shortcuts the builder used on this house, it's a wonder how it even passed inspections before we bought it several years ago. I always dread the winter months (Chicago) because of how cold this house gets and how taxing the constant energy use is on our furnace. Thank you for teaching us something new to check out in our attic once these frigid temps pass. Regardless of what you make, you truly need a pay raise. Thank you again for sharing your knowledge! 😊👍
Hi there, thanks for the compliment! We certainly try, and effectively air sealing the attic floor of a home will often transform how that homes "performs" both in hot and cold temperature extremes. It will also reduce the chances for having mold issues on the underside of your roof. Good luck to you! Andy
Wow, now that was a phenomenal how-to/instructional/proof-of-work/commercial video! Hard to argue with that quality. Slow is smooth and smooth is fast. Wonder if Andy was in the military because he carries himself and has me confident in his team. Still making men in Pittsburgh!
THank you so much for this video! WOW... I've contacted so many contractors and only of them could provide a solution or even had a sense of understanding where my attic moisture was coming from. I've been unimpressed with some of the contractors I have in my city. I've given them the time and freedom to explore and identify the problems, and only one of them took the time to really problem solve and not jump to conclusions. I was getting the "it can't be that - THIS is the problem" ... and from a different contractor it was a "It can't be this - THAT is the problem". But I get it, its hard work. And I give respect to the ones that took the effort to troubleshoot. Being a homeowner is also a lot of work too, especially when we are also ones buying a resp. mask / hazard suit and going into the attic to show them what some of them were too lazy to find.
This! The most frustrating aspect of finding someone I can trust to do work. I've literally had contractors not even peek into the attic to investigate before offering a solution.
Hi and thank for the compliment and watching the video! They can be hard to find, but when possible try to work with companies that use building science based methodologies. If you don't you're likely going to wind up with exactly what you've encountered. A lot of probably good, probably hard working people that simply haven't had the building science training to understand how many of these problems develop. At that point things just devolve to their own anecdotal experiences or what they've heard from other guys...and this is often just not good enough. Andy
Yes, my sales staff ALWAYS go into the attics and document things with pictures. Otherwise...the blow and go team will show up, blow everything in, and then you've got a bathroom fan covered in insulation --- still blowing into the attic. Dumbness-Fest.
Hi there Frank, thanks so much for saying! We certainly try here at Insulwise, and air sealing attic floors has been an integral part of our operation since we first began in 2009. Cheers my friend! Andy
I would have liked to see a blower door test result before and after. That process you showed is a huge improvement. Don’t forget about the sub-rim joist. Up to 20% of loss is there. Cut the foam to fit leaving about 1/4-1/2 inch all around and use the same foam to seal it. Then put an R-15 Rockwool over the foam all the way around. You do both of these and the comfort level of your home will be unbelievably improved.
Hey there thanks for the comment! I will do another video that shows us doing a blower door test in and out with this type of job for sure. We often do also spray foam rim joists in houses. Your method of cutting the foam board definitely works, but can get tricky around wires and tough to reach areas. We spray foam rim joists with 2 part, closed cell foam for that reason. But you're correct in stating that the impact on comfort achieved from doing an attic and rim joists is often dramatic, not to mention the improvement in the home's energy efficiency. Thanks! Andy
Thank you and I'm glad that you found this helpful. You definitely want to make sure that your attic floor is sealed as well as it can be before re-insulating. Andy
Great question, but we only install soffit baffles when the home has soffit ventilation. Many of the homes in our area were built without overhangs or soffit vents. In this case we install slant back vents to add intake ventilation. Andy
Amazing video! For homes with a crawl space do you recommend a similar exercise below the subfloor? How would somebody best insulate/seal between the joists, ideally without having to seal/condition the entire crawlspace itself (much larger undertaking)
Thank you! Crawl spaces are a different beast entirely. When possible you want to encapsulate them. If you're not familiar with that process you want to look it up. Vented crawl spaces are never ideal if that's what you have there.
nice job. I need a good company like you guys to recommend to my customers here in NJ. People think installing a new system is going to solve all of their problems.
Thank you! And yes, a new HVAC system can help and even mask a number of problems, but this solution dramatically lowers the heating and cooling load of a home, making the HVAC system's job A LOT easier. Andy
Looks like button board/lath mesh plaster on top. walls. Identical to my house. Thanks for sharing. I've used duct seal putty on wires and boxes. but should foam the top plates.
Thanks! The ceiling in this home was actually just regular drywall, it was built in the late 1960's. I would highly recommend that you seal the top plates. In many cases that we see, the allow significant amounts of heated air to escape from the home to the attic. Andy
@@insulwiseenergycomfortsolu3293Thanks, i'll start on it. I can tell it's bad when my whole house big ceiling fan is on, bathroom outlets lets the stinky attic air back down, it recirculates it.
I'd love to see the same thing for crawl spaces! I know people do fully conditioned attics and crawl spaces, but for most of us that's not an option, so I'd love to see this same technique applied to a crawl space!
This video is so helpful. It’s the most informative one I’ve found. I’m mustering up the courage to try to do this myself. My attics is very similar to the one in the video, but with soffet vents. I’m trying to decide which product to get. Thought I had decided on caulk, but now leaning towards foam. I’m very impressed by your video, and the way you respond to the comments in here is above and beyond. I’m reading every one. Thank you so much!!
Hi there, thanks! Foam is definitely the way to go, and regular great stuff with a plastic straw works just as good. Draw a map from below, get a headlamp, knee pads, gloves, a good dust mask and have at it. The last important tip is ALWAYS keeping your weight on the floor joists. Things will go wrong in a hurry for you if you don't ; ) Andy
Thanks for the detailed video. I am about to do this for my home, so this is a big help. My question is how do you seal the exterior wall top plates and wire holes? It looks like you have a 6:12 roof and even laying on a board I can't see how you can get close enough to pull back the insulation and see what you are doing. Mine is worse with a 4:12 pitch and blown in cellulose on top of the batts.
Thank you and great question. In homes with low pitch roofs we cannot get to those exterior plates where the roof comes down to seal them. However, if the exterior walls are already insulated that will slow down the air loss rate, so they're not quite as critical as the interior plates where the walls are uninsulated. When we do have access to exterior plates and pull back the fiberglass there it is not nearly as dark and dusty (proof of air leakage) as the batts are that are over interior walls. Andy
Great video, great tips on the ceiling mounted fixtures. I initially went up into the attic in search of some leaky drop soffits which were causing a cold kitchen, but happened to have found many many issues. Horribly wind washed soffits, massive penetrations at the chimney, wide open soffits where mice had gotten in, and more. Problem is I cannot get to many of these locations due to the shallow pitch of the roof towards the eaves. That also includes part of the kitchen soffit. May have to wait until spring and budget to completely reinsulate.
Hi there thanks for the compliment! Yes I know exactly what you are talking about with low sloping roofs. It is exceedingly difficult to get access to these areas sometimes. Also where there are drop soffits (we call them bulkheads here), it is likely that the exterior wall stud bays are also open directly to the attic. What we try to do is make sure that any light fixtures inside the drop soffit are ideally IC rated, or at a minimum have LED bulbs installed in them (they don't create much heat). We then then insert a fill tube down into the exterior wall bays (usually while laying on your stomach) and dense pack the exterior walls that are open, and then blow the drop soffit full of cellulose. If the homeowner has plans to remove the drop soffits then we cap them with foam board and foam sealant like you see in this video. Either way, working in attics with low sloping roofs is usually quite tricky. Taking up a small board or sheet of plywood to lay on is often a great help. But once the air sealing work has been effectively done (and ideally the attic insulated to an R-49 with cellulose insulation), you will see massive improvements in your home's comfort as well as energy efficiency. Andy
@@johnpacella9519 You're welcome John thanks. We try to satisfy everyone, but as you know that's tricky. I think we do a good job with most people who are reasonable however. At least that's what we shoot for! Andy
It looks like you did a great job, but it also looks like you’re completely closed off the soffit vents for proper airflow in the attic space when you added insulation? Also, what is the best way to seal up the attic access panel? Thanks.
Thanks for commenting! This is the most commonly asked question. The house had no soffit vents or overhangs. We added intake ventilation along the back of the roof in the form of slant back roofs. If there are no soffit vents we don't install baffles. The cellulose naturally settles away from the underside of the roof by about half an inch after blowing. It causes no problems in the homes that we work in. This is the best way to seal an access panel. Let me know if you have questions. ua-cam.com/video/1CoYbMxrkXM/v-deo.html Andy
Great video. Curious: in colder north areas older houses have similar kraft paper backed paper that (i think) act as a vapor barrier. Are these stappled from underneat the rafters ? If you remove the insulation, or break that kraft paper does it lead to additionnal humid air in the attic? My house has drywall + forence + kraft back paper fiberglass insulation. I was planning to remove fiberglass insulation, replace with a few layers of rockwool but was concerned that I would not have the kraft paper backed insulation that act as a (minimal) humidity barrier.
Thank you! The kraft paper doesn't work even in the slightest as an effective vapor barrier, from what I have observed. What should be your vapor barrier is your drywall ceiling with a few layers of paint, and then having all of the penetrations / air leaks in your attic floor sealed with foam before you re-insulate. I have seen rock wool becoming more popular lately, if you have a minute could you let me know why you're looking to use that versus something like cellulose insulation? Thanks, Andy
Lots of people ask this. This house was not built with soffit overhang, so we installed slant back vents on the back of the home to allow the ridge vent to draw outside air. You can see the light coming in from them toward the end of the video. We would NEVER block existing soffit vents. Andy
10" of cellulose was R-30 at the time. As l recall 14" was R-30 for blown fibreglass. Keep in mind with an pull down attic ladder in the garage with a garage door open the potential for blowing insulation is greatly increased.
Thanks, when cellulose settles after getting blown in, it actually becomes fairly resistant to being blown around in attics, even when close to whole house fans. Blown fiberglass is much more likely to be "wind washed" like this. Andy
Thank you! One of our team members came up with it years ago. There are very, very few penetrations that cannot be mapped from below. You cannot see where every wire hole or plumbing stack pipe is, but if you are following your map of where the top plates of the walls are --- than you will absolutely find every wire hole and plumbing penetration. Thanks! Andy
We have a shed-type sunroom attached to the back of our home. There’s no way to seal the top plates since we can’t get to them because of the ceiling. Do you have any suggestions for sealing any leaks? We did seal around the ceiling lights because we felt air escaping. Would it help to seal around the top of each wall on the inside and the ceiling? The room is all shiplap including the ceiling. Great video - we will definitely be applying your techniques in the remainder of our home.
Thanks for the compliment! Air sealing the lights in the ceiling would have been super helpful. If there are gaps between the shiplap that can be caulked that would be the next step. Also caulk around any baseboard or crown molding on the ceiling where air could be escaping. Last would be getting the switch and outlets boxes sealed. The foam inserts would be the easiest thing there. Hope this helps! Andy
I am insulating and airsealing my attic a little at a time during the cool months in the hot and humid Texas gulfcoast. I have a bulkhead that I plan to fill with dense packed cellulose, cap with foamboard, and then air seal. Do I put the foil side up or down? Also, I have a cathedral wall in the attic. I want to fill the 2x4 wall with batts and then cover with foamboard, but I don't know what kind of foamboard to use with the faced fiberglass batts.(I don't want to trap moisture.) I see where you used house wrap, but I would only need a small amount to do the job which is why I would prefer to use foamboard. TIA
Hi there, in your application I don't think it will matter much which side is facing outward to be honest. When we use foamboard to cover exposed walls in attics we face the foil side outward toward the roof because it then acts as a radiant barrier and reflects heat back toward the roof. In your situation it sounds like it will be covered with insulation on both sides? For the cathedral I would attempt to use 2" thick polyiso board. That will give you an R-Value of about R-13 and will likely not allow the inner surface to get cold enough to allow water vapor to condense on it. That's the theory anyway. Hope this helps! Andy
Is this the case even with super old homes? (1920's midwest worker home) Our bathroom never had an exhaust fan installed, so I just got that done before the cold snap came through, but we still have frost on the underside of the roof. Worried that sealing things up will lead to mold growth on the underside of our ceiling by not allowing the higher humidity in our home to vent into the attic. I guess we need to lower our humidity throughout the house, but that's a bit difficult to do when the wife suffers from sleep apnea and benefits from a humidifier when we sleep.
Yes, all homes that have attics have air leaks hidden everywhere in them. Nice work getting the bathroom vent in. Did you vent that to the outside through the roof or gable wall? You shouldn't get mold growth on your inside walls / ceiling unless there is missing insulation in an area. Those areas can get cold and water can condense there with eventual mold growth. If you can air seal the attic floor, you will have naturally higher humidity inside the home because you're not constantly losing warm air and water vapor from inside the home to the attic. Andy
Canless...so you mean like the flatter, pancake style LED lights? If so, what we do is use 1/2" thick foam insulation board (both polyiso and XPS board work well). We cut it and shape it so that there is a 4" clearance between the light and the sides of the box. Even though LED's should not create much heat, we still want to have a bit of leeway so that too much heat cannot build up. You can them seal it to the attic floor with foam sealant, or even tape together using metallic hvac tape in a pinch. But at some point you want to use foam sealant to seal and anchor it to the attic floor. Over time tapes will often become unreliable. You could also seal it to the ceiling from below by caulking around the perimeter. Hope this helps! Andy
I bought my multi level (1960) back in 2011 here in Pittsburgh. At the closing the son of the original owners said to me that his mom could never get warm in the house. The air leaks I found over the years and sealed I can understand why the poor woman was always cold in the winter. Most of the leaks were caused by the builder and other contractors who worked on the house over the years. It was bad folks the amount of various air leaks went from minor to major were plentiful. The worst area in the house that I thought was going to be an hour to an hour and half job was air sealing the garage and the stairwell up to the next level. That section alone was a seven to eight hour experience. I'd find one leak, look up, right, left or behind me and find another one. I really hate the builder and anyone that drilled and made holes in that part of the house. They'd cut a hole then just stuff insulation into it instead of fixing it right. Drill a hole and run a wire but not seal up the hole around the wire. If you have the time to do it yourself, plan on spending a lot of time over a number of weeks if you have an older home. It's not an expensive job, your looking at $100 to maybe $300 in supplies and tools to do it yourself but expect to rack up a whole lot of hours. It's not so much sealing the leaks, it's spending the time hunting them down, then finding a solution to seal it up. If time is not on your side because of family, work, age, hire someone to properly air seal your home you'll be glad you did. Plus most states and or power companies, offer generous rebates to home owners that have a certified energy efficiency companies seal and insulate their homes.
Hey there thanks for the comment. We call them stairwell voids and in this video you can see what it looks like after we have sealed a huge one. The air leaks alone can make a house extremely expensive and also difficult to heat and cool.
@@insulwiseenergycomfortsolu3293The stairs coming out of the garage have the stairs going to third level above them. Cold air in the garage could have easily seeped under those interior upper level stairs. The ceiling above the upper steps is flat, no drop area in the attic. Sealing the gap of the drywall ceiling in the garage where it meets the cinder block walls also made a big change. Think about an 1/32 inch gap, that runs the perimeter of a garage, that's 25 ft x 23 ft. It quickly adds up to a major opening to outside air. The other big change with sealing the garage and that stairwell was an almost total elimination of creepy crawly things inside my home.
I’ve noticed a building science trend where builders are favoring air sealing the rafters and making the attic into conditioned, air-sealed space. Matt Risinger from the Build show seems to talk a lot about it from the new home building perspective, but I’d imagine that level of effort may be even more challenging to get the right level of insulation in the attic.
You are correct, and I've seen that video. I believe that a MASSIVE issue that he leaves out is the type of foam that should absolutely be used if you insulate the underside of the roof. In his video I am almost positive that he used open cell foam, which is no no because it does not create a vapor barrier. That means water vapor can move through it and get trapped against the underside of your wooden roof. You DO NOT want this potential. The "hot roof" solution can work well, but it should only be done if you are going to use closed cell foam. Closed cell foam is much more expensive, but at 2" thickness creates an effective moisture barrier (last time I checked). We have seen roof rot issues in Pittsburgh from using open cell foam to insulate the underside of roofs. If you google this and sniff around on the web a bit, you can verify this quickly. Thanks! Andy
One major issue that makes it cost-prohibitive to retro fit from a ventilated attic is if you have a conventional gas furnace in the attic space, which is typical in homes without basements. That would have to be replaced with a heat-pump, or would have to have the gas furnace moved elsewhere.
Great video. I recently had someone look at my attic’s insulation and I asked about air sealing. The rep told me I did not need it bc of the climate in TN. After watching your video, I know that isn’t true.
Thanks! Yes, don't hire this company. Look for a company that's building science based (BPI or RESNET training). Anyone that tells you that an attic does not need air sealed is ignorant of these processes. I have felt air conditioning blasting my hands through attic air leaks on hot summer days Many times. Even if the air isn't rising from winter time stack effect, it can still escape via imbalances in duct systems. Andy
Great video, and I wish I'd watched this video before choosing an insulation company last year. They did not go through these steps and properly sealed any air gaps and blew all the insulation in. I saw you drawing the map of lights and fire alarms and etc, but if the insulation is already blew in, how could anyone properly identify and seal those gaps with those foams? Thanks for your advice.
Well, it’s a shame they didn’t air seal the attic first, but that is unfortunately quite common. It is still possible, but not easy. Our teams at Insulwise do it everyday, but it takes some training, patience, planning (as in mapping out the air leaks), and also a willingness to get dirty. It is also more dangerous as the floor joists are obscured. You’d need a headlamp, knee pads, minimum N95 respirator, foam, a willingness to get dirty and a bit uncomfortable for several hours, and some persistence. But it is possible! Andy
Thank you for your reply. That’s what I thought but was wondering if there was any trick. Know any highly recommended experienced technician around Seattle area? Just trying my luck.
Good to point that out. For customers that expected to do wiring work later we have hung flags from the roof rafters to indicate where they were located. Otherwise it's going to take a bit more time. Thanks! Andy
When you have insulated flex ductwork in the attic that “spiders” off of the main trunk, does it get buried underneath the blown in insulation? I don’t have any experience with the blown insulation and wondered if there was a risk of it collapsing the flex duct if it was buried?
Hi there, best approach for dealing with flex duct in an attic is to make sure that you've first sealed the connections to the trunk line / main trunk as tightly as you can. We see collars / take offs poorly attached and leaking massively all the time. You also need to seal the register boots to the attic floor with foam. Once you've been able to get the duct connections air sealed, then yes, you want to cover / encapsulate the flex lines with blown insulation to add extra R-Value. It will not collapse flex duct lines. Andy
Some questions - should a homeowner consider insulating the ceiling of the attic. I see in the video you left it uninsulated. Is that the norm? Is there a benefit to insulating it? Or, maybe that would only be done if the floor of the attic is covered in board (eg plywood) if the homeowner wants to use it to store boxes (christmas lights and the like)?
Hi there, the only time it could be recommended to insulate the underside of the roof deck is if the home has an extensive HVAC system in the attic. And if you do that you NEED to use closed cell foam (because it has a vapor barrier) and closed cell foam is very expensive. We believe in the vast majority of the time there is more risk and added expense than benefit to insulating the underside of the roof. When homeowners want to use the attic for storage we build them raised storage platforms. We have another video that shows that process if you're interested. Thanks! Andy
Unfortunately almost never, unless it was built as an energy star home and tested with a blower door when finished. Usually if they do anything they will hit the wire holes and plumbing pipe penetrations. The top plates and lots of other misc leaks are almost never sealed.
Would you mind specifying the name brand / model number of the orange foam you were using? I live in Louisiana. I want to air seal my attic - a little at a time - just methodically work my way through it. Then I want to staple radiant barrier Mylar to the upper roof rafters to reflect heat OUT. Finally I want to get someone to come blow in cellulose all over the give me a nice warm blanket. Also - do you have a video that shows how you check/seal air leaks in existing duct work for A/C that’s in the attic space? Also - last question - most all my plumbing up there is PEX. Do you recommend that I sleeve all of that as I uncover and find it? I like what you do. I’m an old engineer and I understand the value of air sealing. What BUGS me is why the hell don’t the damn builders do this BEFORE they insulate? It’s like they are skipping a huge step and honestly they could market themselves as doing it when others don’t/wont!
In this video I used a great stuff foam gun and regular great stuff foam. That said, using regular $4-5 a can great stuff with the plastic straw works just as well, it just takes a bit longer to cure. The cheaper cans can also be more readily maneuvered into tight situations than the gun foam cans as well. Andy
Can't imagine how long this takes in the attics of some older homes. I renovated my grandfathers old home that was built in the 50s and the attic gets very hot. Seems like you'd pay an arm and a leg for the amount of time it would take to go through that entire attic and do this... I wanted to install some solar fans but read if the attic isn't properly sealed it can actually suck cool air out of your home?
Hi, if you're doing it solo than yes and it's going to take some time, but if you draw a map you can isolate the attic into quadrants and do it one section at a time. It is also true that power roof fans can depressurize an attic and pull the AC from the house or heat (if they're also equipped with humidistats for the winter). Best practice is to thoroughly air seal the attic floor, then get the roof properly ventilated, and then insulate the attic floor to an R-49 level (we prefer cellulose insulation). Andy
How to walk through those blown-in cellulose if I need to checkout any roof leak damage? What if minor roof water leak, how to handle the wet cellulose ?
Hey there good questions. If you need to get through it I'd recommend getting knee pads, a dust mask, and a head lamp. You want your hands to be free in an attic. You will need to use your feet to feel for the floor joists while using your hands to hold onto the roof rafters for support. After you have looked at the area you can brush the cellulose back into place with your feet, hands, or a broom. It's easy to do. But --- BE careful. We are practiced at doing this, but novices can fall through their ceiling if they're not careful. Also, the cellulose should be fine. Here is a link to a video that I took that shows what happens to cellulose after a roof leak. It's fine so long as it can dry out. ua-cam.com/video/2XQK-Ba1hWc/v-deo.html&pp=ygUXaW5zdWx3aXNlIHdldCBjZWxsdWxvc2U%3D Andy
Hi there, the foam gun that I use in the video is a basic Great Stuff foam gun that can be purchased in most Home Depot or Lowe's stores. However, we also often use the basic off-the-shelf cans of Great Stuff that go for about $5. The flexible plastic straws and smaller can size allow us to more easily air seal the air leaks that we find that are in tighter spaces. That stuff works just as well, just without the fancy gun. The guns like I use in the video also need to be cleaned after they're used or they clog up. Hope this helps! Andy
You can do it this way too IF you are going to use closed cell foam. Many foam contractors will use open cell foam for this, which is a no no (can contribute to / cause your roof to rot and we have seen this happen in Pittsburgh). However, closed cell foam is very expensive, so most homeowners do not want to pay for this. In fact most foam contractors don't even bring it up. Our philosophy is to allow the roof to operate independently of the air and thermal barrier at the top of the home. When done correctly, this is far less expensive than using closed cell foam, far safer for your roof than using open cell foam, and a highly effective and economical solution. Andy
Hi there, good question. In this case we did not because this home did not have existing soffit ventilation. The gutters are hung literally on the tops of the exterior walls at the edge of the roof. That said, attics ALWAYS should have both intake and exhaust ventilation (but well sized gable vents on homes that have somewhat of an east/ west alignment to catch the breeze also tend to do extremely well). At this home we installed 4 slant back vents just above the insulation layer. You can see light pouring through some of them as I pan across across the back portion of the attic / home. Thanks, Andy
Thanks! Polyurethane caulk would work just fine in some cases. The reason we like foam is because it is far less expensive, expands to seal all kinds of varied penetrations, can fill voids as wide as 4-6" inches when you learn how to use it correctly, the can and straw can fit into LOTS of tight and difficult to reach areas, like plumbing penetrations that are close to the edges of roof decks, etc, and the cans don't freeze. I've had tubes of caulk freeze in the back of a truck and then become unusable. Cans of Great Stuff can sit in a truck at 0 degrees for weeks, then after running some hot water over them they're ready to go. Hope this helps! Andy
Wood is permeable, but drywall with a few layers of paint on it is generally a "pretty decent" vapor barrier. Think of your bathroom ceiling after taking a hot steamy shower if you haven't turned on a fan, it will be dripping. We seal the penetrations, and then make sure the roof is properly ventilated. If both of these measures are done correctly, it is exceptionally rare to later have a problem with excessive moisture or mold in an attic space. Andy
I have blown in cellulose thats about 12 inches, i went into my attic to air seal and it was impossible , too much cellulose. I ended up finding the pvc vent protrusions and sealed the holes that they came up theough and then called it a day lol. Will it be beneficial to seal everything from inside the home instead? I did all outlets and a few lights.
Hey there, yes it is definitely a chore to air seal when blown in cellulose is present, especially when there is a lot of it. We do have to deal with this from time to time here. And it would be this type of situation where drawing a map of the air leaks before going into the attic would be most helpful. It's just too difficult to find them all otherwise. What we do is standard knee pads, gloves, headlamps, and respirator, and then move methodically through it, sealing as you go. You will be covered in cellulose as you move it out of the way. Your whole attic look like a series of lumps and piles when you're done. At that point we would move back through it and use something like a house hold broom to "swoosh" it back into place so that it's even. Air sealing an attic that is already blown with cellulose is definitely not for the faint of heart. I think it would be nearly impossible to do a good job air sealing from the inside once the house has been finished. You would never be able to get the top plates, wire holes, around bath fans, junction boxes, etc. There are types of recessed lights that can be sealed from the inside, but my guess is that you'd miss 90-95% of the penetrations in the attic floor. That said, I give you credit for trying! Andy
We often just use regular Great Stuff for $5 a can. It does just as good of a job and is much less expensive. If your house has a fire, and won't be the type of foam that you used for attic air sealing that makes or breaks the damage the fire does.
@@insulwiseenergycomfortsolu3293 thanks for tip. Like your videos. I gotta say, you guys earn your keep! I am about sick of doing my own attic. I used to say if I went into a trade instead of a desk job I would have done HVAC. I recant my earlier statement after crawling around in our attic for several days. Lol
It sounds like there weren’t soffit vents in this attic, what would you recommend doing to prevent blocking the soffit vents when you blow in the cellulose?
There was zero overhang on this house. If you had an overhang but no soffit vents, we would first stuff / block the overhang with fiberglass and then install roof ventilation in order to get the attic properly ventilated. Andy
Not a bad idea at all. If you add in a running blower door it gets even clearer. However, if you simply assume that every penetration in the attic floor that you find is an air leak (top plate, wire hole, plumbing stack pipe, gaps around bath fans, recessed lights, etc), and seal it with foam, you should have the same outcome. You're not going to get measurable air leakage through solid drywall, plaster, or framing lumber. Andy
@@insulwiseenergycomfortsolu3293 Like others, my rafter bays are not blocked so air will flow from soffit to soffit in this cape cod's upper floor. You can really see it with the thermal. Now I'm just trying to figure out which foam gun will work best. Looks like the Great Stuff Pro14 has the least offenses.
All of my walls running north to south seem to have have top plates, which I believe to be on top of the gaps in the walls. There seems to be no visible gap between the plates and the drywall below it. Should I still be adding spray foam along the sides of these? I tried a few times to see what would happen, but the foam kinda just goes everywhere even when spraying it slowly. East to west walls seem to be normal and I am finding the gaps/wires/other holes fine and filling them. Maybe it is just the way the construction was done, the building was made in 1960 and I know plaster was used a lot for walls and ceilings back then.
Hi there, we seal the plates regardless of the appearance of the plates in terms of visible gaps or no visible gaps. It's just a matter of habit and keeps our teams from trying to make that judgement. But if you're having difficulty getting the foam to lay where you want it to, you might not be able to do it. It doesn't sound like the plates in question are big leakers though so you may ok not doing them. Hope this helps! Andy
Thanks for the reply. I am actually really glad I came across this channel. There are many tips which I never found elsewhere (like the dust lines under the insulation). Do you have any tips for finding sections of the attic, which have no insulation under the top sheets?. While air sealing I have noticed some sections of the attic seem to have no insulation above the ceiling except a sheet of insulation, which is laying across the beams. Is the only way to really find all of them to pull back every sheet and lock? This wouldn't be a huge problem to do while putting up the baffles, but I was hopeful there was a better way. @@insulwiseenergycomfortsolu3293
@@xSatansGiftx Hi there and thank you! I'm not sure what you mean by sheets of insulation. Do you mean pink batts of fiberglass are laying across the studs? Sheets of foam board? Usually the ceiling fixtures, light switches, bulk heads, walls, etc give you a strong idea for where most of your air leaks will be from below. The ones you can't see from below are plumbing stack pipes that run up through the walls. But if you don't have a bathroom or kitchen in the vicinity of that area, you are likely to not have a plumbing pipe running up through a top plate there. Let me know about the sheets of insulation. Andy
Yes I mean the batts of insulation. In my attic there is some sort of older yellow fiber glass that looks like big cotton balls and the batts laying over top of this. I have noticed while air sealing, that some areas under the batts do not have this yellow insulation and I can see the bare ceiling (after pulling back the batts). I was just hoping you possibly knew a good way to find these spots without moving back every sheet to see the places missing insulation. I am going to be putting in blown in insulation and I am going to try and fill these empty areas under the batts. If the best solution is just to move every batt and look under it, I will just do that. I was just hoping there was some easy way to find these bare ceiling areas. Thanks for the reply again.@@insulwiseenergycomfortsolu3293
Hi Dan, good observation. We didn't install ventilation baffles because this home did not have any soffit vents or intake ventilation of any kind. We added intake ventilation in the form of a series of slant back vents that we installed just above the insulation line on the back of the home. You can see some of these in the last segment of the video. We sealed the exterior side-wall top plates, but not the front or back exterior top plates due to the low slope. We sometimes offer to spray foam these difficult to reach top plates with two part foam, but due to the significant added cost we only recommend doing this in certain critical situations. That said, all of the exterior walls in this home were insulated with fiberglass batts. The presence of these batts does a decent, but not perfect job of knocking down air flow through them, so we didn't recommend the added expense of spray foaming them with two part foam. Hope this helps! Andy
This attic had zero intake ventilation. We needed to install it in order to balance the ridge vent (exhaust ventilation). We did this by installing a series of slant back vents along the back of the house. That is the light that you see coming through. Andy
I don't see any chimneys... But what if there was a wood burning fireplace flue penetration? Yiu aren't supposed to be within two inches of the flue... So how can air leaks be prevented there?
You CAN seal around hot flues and chimneys, but it requires a specific process. We cut sheet metal to conform around or butt against the flue or chimney, and then seal the sheet metal to the flue or chimney using HTV (high temperature) silicone. We then wrap either a fiberglass or rock wool batt around the flue pipe or chimney before blowing in cellulose insulation around the area. The main thing is using something to air seal that either cannot combust (sheet metal) or is designed for high heat applications (htv silicone). Hope this helps! Andy
My attic has 6-8 in. of cellulose. Will put more because I noticed when I turn heater on then off my hear escapes a couple minutes later. Should a crawl space also be insulated? Thank you! Any tips recommended
Hi there sorry for the delay. Before you add insulation to an attic you first want to air seal it like we do in this video. But yes, doing both air sealing and insulation work will definitely help the heat to stay in your home more efficiently. Most crawl spaces should be encapsulated. That means insulating and air sealing the walls and then installing a vapor barrier on the ground. Andy
This house had no soffit vents, the gutter was hung directly on the exterior wall (there was no overhang). We installed slant back vents on the back of the home to provide a means for intake ventilation. You can see light shining through from some of them at the end of the video. Andy
If there are air ducts that come up from the house and into the attic, we seal around the ducts with 1/2" foam board and then foam sealant, but any solid material can be used like plywood or even heavy cardboard in a pinch. The goal is to eliminate any way for air from inside the home to communicate with or transfer to the attic. Andy
I'm assuming that you have to pull and leave the insulation off the exposed top plates to allow the foam to cure and dry? How long do you usually wait before placing the insulation back over the areas where you sealed the top plates?
You can do that and it may be better in some cases, but we do is inject the foam down into the top plate cracks, wire holes, plumbing penetrations, etc. That way if the batt falls back onto the area that you've just air sealed, it's far less likely to push the foam off of the air leak. Andy
@@ajamesc55 My experience has been that foams used from guns like the one shown in our video harden / cure within minutes, but the cheaper foams like Great Stuff for $4-5 a can can take 30-60 minutes to cure depending on temperature. The cheap stuff works just as well, you just have to be a bit more cognizant of not smearing it until it cures. Andy
I might have missed it if you mentioned it, but if there is pre-existing cellulose in an attic, does that need to be removed before air sealing top plates? Can it impact curing if insulation goes back over wet foam?
Hi Joe, you can definitely air seal if there is pre-existing cellulose insulation present. However, it is considerably more time consuming and less fun. Depending on how much is present, it can be a bit like pushing sand around at the beach where you move some, and then it falls back down into the area you were attempting to move it from. You just have to patient with it, organized, draw a good map from below so that you know where and what you're looking for, be methodical, and lastly double check your work --- even if you did it yourself. If a bit of insulation gets onto the foam it won't affect the curing. But if you completely swipe away the bead of foam with your glove or foot, that's a different matter. We air seal attics that are insulated with varying degrees of cellulose fairly often. Hope this helps! Andy
@@insulwiseenergycomfortsolu3293 Thanks for the quick reply! That's good to know, we had a company air seal our attic, add soffit vents/baffles, and add more insulation on top of our existing cellulose. But recently had a blower door test with thermal imaging and it looks like top plate spots were missed or the sealant didn't cure, so trying to get an idea of what's common practice.
@@joelalonde In our area, many of our competitors say that they "air seal." They don't (or at best they do a totally lamo job doing it). Air sealing an attic is difficult, tedious work and lots of companies 1) aren't truly committed to it 2) don't have staff that fully understand how to do it 3) don't want to pay the added expense of time and materials for doing it right, etc. Now, there are some places where we can't always effectively seal top plates, like exterior walls of a low sloping roof. But all of the other places we make a serious effort to get to. However -- it is easy to check to see if they hit the plates or not. If you put your hand down through the cellulose where the top plates, bathroom fans, plumbing stack pipes, etc are, you will either feel a bead of foam on the thing in question --- or you will not. If you don't feel a semi-hard bead of foam -- it didn't get sealed. Andy
What would it cost to remove old insulation, do pest control spray, air seal all openings, and install sealant and do r38 or R49 insulation on 3K sq. ft. area?
Every house is different, even with the specifications that you provided. If you are in the Pittsburgh area just give us a call and we'll happily come out and quote your project free of charge. Thanks!
@insulwiseenergycomfortsolu3293 7 hours ago It's tough for me to give an exact figure because every attic is different, even homes in plans that are next door to each other. We generally charge about $1 per sq ft for air sealing, and then extra for large items like stair well voids, bulkheads (dropped ceiling areas), recessed lights, etc. We then charge an additional amount for adding in the extra cellulose insulation at the end, and that depends on how many inches we need to blow in to finish with a combined R-49 insulation level (generally about 15" inches total). Hope this helps! Andy
It certainly gets cold here during the winter, but we work in attics year round. There is definitely an adjustment phase to dealing with the heat! Andy
Where the shower bulk heads and stairs were sealed seems like the moisture would get trapped in the pockets. Have you ever been back to one years later? Especially the bathroom ones.
Hi, there's only a problem with moisture and water vapor if there is a surface present that gets cold enough for water vapor to condense. If this happens mold can start to grow. However, these "pockets" are fully within the conditioned space of the home, and there is a full layer of insulation on top of them. So there is no issue. These are common ways for air sealing cavities in floors of attics. We've been utilizing these same solutions for 15 years in thousands of homes, there's no issues. Thanks, Andy
I havent seen anyone address what happens with balloon framed houses. Ours is 1915 vintage. Had insufficient blown in, needed to remove knob and tube wiring. Debating the best way to plug off openings down into wall stud bays. I'm guessing having blown in cellulose go in, then some sort of plug? Costs matter
Hi, we encounter this type of home a few times every year. Definitely have the knob and tube wiring removed first. We insist on that being done in the homes that we work in. But, if you find a team that can effectively dense pack cellulose insulation, you first want to 1) plug the bottoms of the stud bays in the basement and then 2) use a fill tube and push it as far down the bays as you can and then dense pack the cellulose insulation into the vertical stud bays. If the team has the right gear and technique, they will be able to hit somewhere between 1/2- 1/3 of the exterior walls this way. We would still drill the entire first floor and beneath the windows. You can cap the tops of the stud bays with foam board and foam sealant if you want. But if the bays have been properly dense packed with cellulose, there will be no air or heat coming up through them once this has been done. Hope this helps! Andy
@@insulwiseenergycomfortsolu3293 thanks so much for responding. I just finished having the remainder of k&t removed. While clearing for their work, I realized I shouldn't ignore some of the attic issues much longer
@@insulwiseenergycomfortsolu3293 I also have been blocking and sealing from the basement, and am about 2/3 way around the perimeter. So much to do, so little time
My question is why? What difference does it make if the cracks are sealed, if it all sits under R60? A little air crack is going to work its way through R60?
Hi Eddie, the answer is yes. Air flow from your house during the winter will absolutely bleed through any type of blown in insulation -- unless it's dense packed but that's a closed cavity solution. We prove this by doing blower door tests in homes with tons of blown in fiberglass (and sometimes even cellulose) all the time.
It's harder but it's the same steps. Draw your map from below, put on your PPE gear, then crawl through the material as carefully as possible to track down the air leaks and seal them. It will suck at first, but you get used to it after a few minutes. You just need to be methodical and not in a hurry.
hi can i put fiberglass rolls over existing blown in cellouse from years ago (settled)that was blown over fiberglass insulation from when the house was built in 1957
You could, but --- the reason that we are not proponents of using batt fiberglass in attics is because it's almost impossible to get the batts to conform around all of the miscellaneous obstructions that are located on the attic floor (plumbing stack pipes, wires, bath fans, recessed lights, the roof rafters at the edge of the roof) and you wind up with lots of gaps. I'll attach a link to my site and you can see some pics to see what I mean. That said, I would do the best that I could with fiberglass batts before I used blown fiberglass. But best choice, at least as we see it, is to use blown in cellulose insulation. Good luck to you! Andy
Did this home not have soffits along the underside of the gutter that vent up to a roof vent?? It looks like the insulation was blown into those areas?
No, this home did not have any soffit vents whatsoever. We installed a series of slant back vents along the back of the roof to provide intake ventilation. You can see the light coming in from one of them in the final part of the video. Andy
Most of the foams are really pretty similar, we like regular Great Stuff for about $5k a can. The biggest difference is that it takes longer to cure than the more expensive foams so it can be messier until you get used to using it. But for an attic application all of them do pretty much the same thing.
Hi, not in this case. If you insulate the stairwell side walls and sloped ceiling you have FAR more area that is exposed to hot and cold temps, versus making it a flat plane on the top. So this method will allow for better energy efficiency. However, when stairwell voids like this abut exterior walls of homes, we do fill them in with cellulose insulation as opposed to capping them. Hope this helps. Andy
Thank you for the compliment! It's tough for me to give an exact figure because every attic is different, even homes in plans that are next door to each other. We generally charge about $1 per sq ft for air sealing, and then extra for large items like stair well voids, bulkheads (dropped ceiling areas), recessed lights, etc. We then charge an additional amount for adding in the extra cellulose insulation at the end, and that depends on how many inches we need to blow in to finish with a combined R-49 insulation level (generally about 15" inches total). Hope this helps! Andy
The cost range is usually $3-6k depending on the attic size, existing insulation level, types and quantities of air leaks to be sealed, vents that may need to be installed, and how the attic hatch is to be addressed. The range varies widely. But if the work is done right, you will be instantly surprised and happy with the effect.
We did not, We map out the air leaks, seal them, and utilize the existing insulation that is there. It makes the project less expensive for the homeowner.
@@insulwiseenergycomfortsolu3293 Ok, I didn't read all of the replies. You explained what you did in this case. I'm trying to determine if I need to ventilate my soffits and then move back my insulation and install baffles in my attic, OR if it is MEANT to be this way for some valid reason and I should leave it alone. This house was built like this in 1978. It does have three vents near the ridge, but the soffits are all sealed up and there is insulation pushed out to the roofline. I'm in South Central Kansas, "Zone 4." We have brutally hot summers with humidity, and brutally cold winters. Both summer and winter can be VERY windy.
@@dolfinwriter5389 Ahhh ok I totally understand. Yes -- if you have an unconditioned, vented attic like you have and the one in this video -- you absolutely want to 1) Have an adequate amount of roof ventilation and 2) make sure that that ventilation is balanced between intake (soffit vents) and exhaust (ridge ventilation). If you do not, the ridge vents have a tendency to exacerbate Stack Effect within the home during winter. This leads to added heat loss and increased risk of attic mold growth as additional water vapor from your home via attic floor air leakage gets deposited into your attic. However -- soffit vents DO increase the risk for a roof getting blown off in a high wind storm event. There is a good argument to be made for using closed cell spray foam (NOT open cell foam. Two entirely different materials) to insulate the underside of the roof in areas like this. It will not only insulate extremely well and also provide a vapor barrier --- but it will increase the structural rigidity of the roof --- and not leave soffit vents as a place where powerful gusts can enter and potentially lift the roof off. However, closed cell spray foam tends to be very expensive. If I were you and had an extra $15-25k sitting around this just might be the direction that I would go. Otherwise, you should find a way to install intake ventilation to balance your exhaust vents. At the home in this video we installed a series of slant back vents along the back of the home, about 4. It's not as good as continuous soffit ventilation or continuous under-shingle intake vents, but it far better than not installing them. After air sealing the attic floor, the exhaust vents will now pull their air from these slant back vents as opposed to the house. This helps to dry the attic from unanticipated moisture intrusion, and dissipate summer heat. You can see light coming in from some of them in the final part of the video. Hope this helps! Andy
Idiots that built my house in 1979, bought home in 2006.. dryer vented to crawl space, and upstairs bathroom vented to attic, downstairs bathroom vented to sofet. I had to re vent for it to go all outside.
We see this all the time. Nice work identifying the issues and correcting them. Some people don't realize these problems until these areas begin rotting from mold growth.
I’m skeptical that sealing every linear inch of the drywall corners is necessary. They’re already taped and sealed on the finish side. But the penetrations definitely need to get sealed.
Hi Tommy, what happens is that the drywall pulls away from the top plates, typically after the studs have shrank a bit from their original moisture percentage going down as they dry out. We have blower door tested these top plate leaks plenty of times, they definitely leak. On this other video here that I took from a home built in the 1990's you can see the black streaks running through the fiberglass immediately over top of the top plates. That is from warm air from the house passing through them and the dust in the air getting trapped in the fiberglass. As there is typically a 1/8" gap or larger on either side of the top plate, when added together the combined air leakage in attics from leaky top plates is typically substantial. Sealing top plates should be a major priority for anyone doing attic air sealing work. Link to top plate air leakage visual proof: ua-cam.com/video/X7GMG3T8cE8/v-deo.html&pp=ygUrYWlyIHNlYWwgYW4gYXR0aWMgdGhhdCBpcyBhbHJlYWR5IGluc3VsYXRlZA%3D%3D Hope this helps. Andy
If you already have R60 blown in insulation, how do you even start to do air sealing after the fact without ruining the R60 blanket and having to re-blow insulation
We have had to air seal attics that have already been blown in with a lot of material, typically blown in fiberglass. You have to displace it as you go, double check that you have in fact hit everything, and then rake it back into place. Cellulose is more difficult to displace, it acts like sand on a beach. But blown fiberglass is actually quite easy. The only drawback with blown fiberglass is that it can compact a good bit while doing this. When we retrofit attics, we always air seal them first, and then blow a fresh blanket of cellulose on top of whatever was there to get it 100% even again. But a homeowner likely would not need to get it that "perfect."
@@insulwiseenergycomfortsolu3293 I just had my attic redone this spring to R60 with blown in fibreglass. Before that I airsealed all I could think of myself, any light fixture, and any wiring holes. Thankfully there are no exhaust fans up there since I have a central exhaust system out the side of my house. But I am also not an expert at it either, so I assume I missed something. Having a energy audit done to get in with some govt grant, I have taken my house from 139 GJ of energy a year to 101 GJ a year, according to their before and after readings, and blower door test. So I must of done something right. But even so, I still have some attic frost (I check a few days into a cold snap when we get them) But I dont think its enough to accumulate into attic rain or anything, or if it does, its so light that it must dry out with ventilation. I have my head in my attic at least a half dozen times per year, just to check that things are ok. Would I like zero frost, 100%. But as well, when you have a low of -35 outside with sometimes relative humidity of 70%, that frost can stick to things inside your attic, just like hoar frost outside. Now that I would like to figure out how to mitigate.
doesn't prior mean before? So are you air sealing an attic before insulation? But the title says How to Air Seal That is Already Insulated. I'll view on...
Yes, it does. I had to try to convey in a short title that we were air sealing an attic that already had insulation in it. We are retrofitting the insulation in existing homes. Nearly all of them have insulation already in them.
This is, by far, the best video I've seen on attic insulation. Great work.
Thank you so much! It was a lot of work!
The metal nozzle screwed onto cans is a very good investment. It greatly reduces the amount of foam waste, which pays for itself. Also, the foam release can be adjusted more efficiently and a longer nozzle reaches further.
The foam guns are helpful, but we do not always use them. We find many areas where they are too large and cumbersome to allow us to seal gaps and openings effectively. In these areas the small cans of Great Stuff come in handy.
Andy
@@insulwiseenergycomfortsolu3293Interesting reply…based on vids of installers trying to demo different types of foam products, by creating several side-by-side “beads” used for comparison, without any nozzle attachment, those comparison beads were not uniform in depth, thickness or alignment. Kind of a mess without using the nozzle piece. IMHO
Don't the attachment nozzles want to plug up?
Good stuff! If it's in the budget, have the insulation contractor pull all the old insulation at the start of the project. Makes it much easier to find & fix all the air leaks.
Thanks! If possible sure that certainly makes the air sealing easier. But if the team doing the work is used to air sealing when there is insulation down, are mapping the air leaks, and testing out with blower doors you can get the same result, and also save the homeowner a few thousand bucks while doing it. That said, I would not trust most of our local competition here to get the results that we get with the insulation still in place. Properly air sealing an attic floor is tedious, time consuming, methodical work -- and that's when the attic temperatures are "friendly".
I can't thank you enough for this video. Very informative and I wish I knew about this a long time ago. Our house seems to get colder every single winter, despite doing everything right with furnace maintenance, weatherproofing gaps, e.t.c. We've uncovered so many shortcuts the builder used on this house, it's a wonder how it even passed inspections before we bought it several years ago. I always dread the winter months (Chicago) because of how cold this house gets and how taxing the constant energy use is on our furnace. Thank you for teaching us something new to check out in our attic once these frigid temps pass. Regardless of what you make, you truly need a pay raise. Thank you again for sharing your knowledge! 😊👍
Hi there, thanks for the compliment! We certainly try, and effectively air sealing the attic floor of a home will often transform how that homes "performs" both in hot and cold temperature extremes. It will also reduce the chances for having mold issues on the underside of your roof. Good luck to you!
Andy
Building code = The least amount of work that can be done without being illegal.
Wow, now that was a phenomenal how-to/instructional/proof-of-work/commercial video! Hard to argue with that quality. Slow is smooth and smooth is fast. Wonder if Andy was in the military because he carries himself and has me confident in his team. Still making men in Pittsburgh!
THank you so much for this video! WOW... I've contacted so many contractors and only of them could provide a solution or even had a sense of understanding where my attic moisture was coming from. I've been unimpressed with some of the contractors I have in my city. I've given them the time and freedom to explore and identify the problems, and only one of them took the time to really problem solve and not jump to conclusions. I was getting the "it can't be that - THIS is the problem" ... and from a different contractor it was a "It can't be this - THAT is the problem". But I get it, its hard work. And I give respect to the ones that took the effort to troubleshoot. Being a homeowner is also a lot of work too, especially when we are also ones buying a resp. mask / hazard suit and going into the attic to show them what some of them were too lazy to find.
This! The most frustrating aspect of finding someone I can trust to do work. I've literally had contractors not even peek into the attic to investigate before offering a solution.
Yeah that's why I'm deciding to just do everything myself, at least I'll know what was done and how it was done
Hi and thank for the compliment and watching the video! They can be hard to find, but when possible try to work with companies that use building science based methodologies. If you don't you're likely going to wind up with exactly what you've encountered. A lot of probably good, probably hard working people that simply haven't had the building science training to understand how many of these problems develop. At that point things just devolve to their own anecdotal experiences or what they've heard from other guys...and this is often just not good enough.
Andy
Yes, my sales staff ALWAYS go into the attics and document things with pictures. Otherwise...the blow and go team will show up, blow everything in, and then you've got a bathroom fan covered in insulation --- still blowing into the attic. Dumbness-Fest.
Proper attic ventilation is key as well.
Soffit vents (not blocked by insulation) and ridge vents are must haves.
Yeah fantastic buddy from a carpenter of 40 years here in England . Top job . Always learning
Hey thanks Paul, glad this helped you!
Andy
By far the best video explaining the air sealing process and why it’s important Iv seen. I will be sharing this with my customers. Truly great job 👏🏻
Hi there Frank, thanks so much for saying! We certainly try here at Insulwise, and air sealing attic floors has been an integral part of our operation since we first began in 2009. Cheers my friend!
Andy
I would have liked to see a blower door test result before and after. That process you showed is a huge improvement. Don’t forget about the sub-rim joist. Up to 20% of loss is there. Cut the foam to fit leaving about 1/4-1/2 inch all around and use the same foam to seal it. Then put an R-15 Rockwool over the foam all the way around. You do both of these and the comfort level of your home will be unbelievably improved.
Hey there thanks for the comment! I will do another video that shows us doing a blower door test in and out with this type of job for sure. We often do also spray foam rim joists in houses. Your method of cutting the foam board definitely works, but can get tricky around wires and tough to reach areas. We spray foam rim joists with 2 part, closed cell foam for that reason. But you're correct in stating that the impact on comfort achieved from doing an attic and rim joists is often dramatic, not to mention the improvement in the home's energy efficiency.
Thanks!
Andy
I appreciate ALL your Insulation Videos - Thankyou!
You're welcome! I'm trying to make the best insulation videos possible.
This is Awesome information! I have an attic insulation job coming up. This information will help me do the best work I can do!
Thank you and I'm glad that you found this helpful. You definitely want to make sure that your attic floor is sealed as well as it can be before re-insulating.
Andy
Great explanation ! Clear and concise for anyone to understand.
Thanks Paul!
Andy
informative. What about baffles to the exterior soffits? Isn’t that important?
Great question, but we only install soffit baffles when the home has soffit ventilation. Many of the homes in our area were built without overhangs or soffit vents. In this case we install slant back vents to add intake ventilation.
Andy
Amazing video! For homes with a crawl space do you recommend a similar exercise below the subfloor? How would somebody best insulate/seal between the joists, ideally without having to seal/condition the entire crawlspace itself (much larger undertaking)
Thank you! Crawl spaces are a different beast entirely. When possible you want to encapsulate them. If you're not familiar with that process you want to look it up. Vented crawl spaces are never ideal if that's what you have there.
nice job. I need a good company like you guys to recommend to my customers here in NJ. People think installing a new system is going to solve all of their problems.
Thank you! And yes, a new HVAC system can help and even mask a number of problems, but this solution dramatically lowers the heating and cooling load of a home, making the HVAC system's job A LOT easier.
Andy
Looks like button board/lath mesh plaster on top. walls. Identical to my house. Thanks for sharing. I've used duct seal putty on wires and boxes. but should foam the top plates.
Thanks! The ceiling in this home was actually just regular drywall, it was built in the late 1960's. I would highly recommend that you seal the top plates. In many cases that we see, the allow significant amounts of heated air to escape from the home to the attic.
Andy
@@insulwiseenergycomfortsolu3293Thanks, i'll start on it. I can tell it's bad when my whole house big ceiling fan is on, bathroom outlets lets the stinky attic air back down, it recirculates it.
I'd love to see the same thing for crawl spaces! I know people do fully conditioned attics and crawl spaces, but for most of us that's not an option, so I'd love to see this same technique applied to a crawl space!
Hey there, we could actually do a video for that as we do what are called "encapsulated" crawl spaces. I'll put that on the list!
Andy
Seconded
What an excellent video, I have big leaks in the attic and I will seal it up this summer. Thank you for making this video.
Your're welcome and I'm glad that it helped!
This video is so helpful. It’s the most informative one I’ve found. I’m mustering up the courage to try to do this myself. My attics is very similar to the one in the video, but with soffet vents. I’m trying to decide which product to get. Thought I had decided on caulk, but now leaning towards foam. I’m very impressed by your video, and the way you respond to the comments in here is above and beyond. I’m reading every one. Thank you so much!!
Hi there, thanks! Foam is definitely the way to go, and regular great stuff with a plastic straw works just as good. Draw a map from below, get a headlamp, knee pads, gloves, a good dust mask and have at it. The last important tip is ALWAYS keeping your weight on the floor joists. Things will go wrong in a hurry for you if you don't ; )
Andy
Thanks for the detailed video. I am about to do this for my home, so this is a big help. My question is how do you seal the exterior wall top plates and wire holes? It looks like you have a 6:12 roof and even laying on a board I can't see how you can get close enough to pull back the insulation and see what you are doing. Mine is worse with a 4:12 pitch and blown in cellulose on top of the batts.
Thank you and great question. In homes with low pitch roofs we cannot get to those exterior plates where the roof comes down to seal them. However, if the exterior walls are already insulated that will slow down the air loss rate, so they're not quite as critical as the interior plates where the walls are uninsulated. When we do have access to exterior plates and pull back the fiberglass there it is not nearly as dark and dusty (proof of air leakage) as the batts are that are over interior walls.
Andy
Great video, great tips on the ceiling mounted fixtures. I initially went up into the attic in search of some leaky drop soffits which were causing a cold kitchen, but happened to have found many many issues. Horribly wind washed soffits, massive penetrations at the chimney, wide open soffits where mice had gotten in, and more. Problem is I cannot get to many of these locations due to the shallow pitch of the roof towards the eaves. That also includes part of the kitchen soffit. May have to wait until spring and budget to completely reinsulate.
Hi there thanks for the compliment! Yes I know exactly what you are talking about with low sloping roofs. It is exceedingly difficult to get access to these areas sometimes. Also where there are drop soffits (we call them bulkheads here), it is likely that the exterior wall stud bays are also open directly to the attic. What we try to do is make sure that any light fixtures inside the drop soffit are ideally IC rated, or at a minimum have LED bulbs installed in them (they don't create much heat). We then then insert a fill tube down into the exterior wall bays (usually while laying on your stomach) and dense pack the exterior walls that are open, and then blow the drop soffit full of cellulose.
If the homeowner has plans to remove the drop soffits then we cap them with foam board and foam sealant like you see in this video. Either way, working in attics with low sloping roofs is usually quite tricky. Taking up a small board or sheet of plywood to lay on is often a great help. But once the air sealing work has been effectively done (and ideally the attic insulated to an R-49 with cellulose insulation), you will see massive improvements in your home's comfort as well as energy efficiency.
Andy
Thanks for the valuable info AND the discussion in the comments. Just goes to show…few customers are 100% satisfied.
@@johnpacella9519 You're welcome John thanks. We try to satisfy everyone, but as you know that's tricky. I think we do a good job with most people who are reasonable however. At least that's what we shoot for!
Andy
Very well explained, thank you
Hi there, thanks for the compliment! We certainly try.
Andy
It looks like you did a great job, but it also looks like you’re completely closed off the soffit vents for proper airflow in the attic space when you added insulation? Also, what is the best way to seal up the attic access panel? Thanks.
Thanks for commenting! This is the most commonly asked question. The house had no soffit vents or overhangs. We added intake ventilation along the back of the roof in the form of slant back roofs. If there are no soffit vents we don't install baffles. The cellulose naturally settles away from the underside of the roof by about half an inch after blowing. It causes no problems in the homes that we work in.
This is the best way to seal an access panel. Let me know if you have questions.
ua-cam.com/video/1CoYbMxrkXM/v-deo.html
Andy
@ thank you for the response! I’ll check out your link.
Great video. Curious: in colder north areas older houses have similar kraft paper backed paper that (i think) act as a vapor barrier. Are these stappled from underneat the rafters ? If you remove the insulation, or break that kraft paper does it lead to additionnal humid air in the attic? My house has drywall + forence + kraft back paper fiberglass insulation. I was planning to remove fiberglass insulation, replace with a few layers of rockwool but was concerned that I would not have the kraft paper backed insulation that act as a (minimal) humidity barrier.
Thank you! The kraft paper doesn't work even in the slightest as an effective vapor barrier, from what I have observed. What should be your vapor barrier is your drywall ceiling with a few layers of paint, and then having all of the penetrations / air leaks in your attic floor sealed with foam before you re-insulate. I have seen rock wool becoming more popular lately, if you have a minute could you let me know why you're looking to use that versus something like cellulose insulation?
Thanks, Andy
Great info!
Glad that you found it helpful!
That is a pretty blanket of cellulose good work
Thank you! Our teams are pretty experienced and this is typically how the finished results look.
Where are the soffit vents for attic venting/Attic Vent Channel? Did you guys close those completely?
Lots of people ask this. This house was not built with soffit overhang, so we installed slant back vents on the back of the home to allow the ridge vent to draw outside air. You can see the light coming in from them toward the end of the video. We would NEVER block existing soffit vents.
Andy
10" of cellulose was R-30 at the time. As l recall 14" was R-30 for blown fibreglass. Keep in mind with an pull down attic ladder in the garage with a garage door open the potential for blowing insulation is greatly increased.
Thanks, when cellulose settles after getting blown in, it actually becomes fairly resistant to being blown around in attics, even when close to whole house fans. Blown fiberglass is much more likely to be "wind washed" like this.
Andy
Wow, that is a great idea to make the map!
Thank you! One of our team members came up with it years ago. There are very, very few penetrations that cannot be mapped from below. You cannot see where every wire hole or plumbing stack pipe is, but if you are following your map of where the top plates of the walls are --- than you will absolutely find every wire hole and plumbing penetration.
Thanks!
Andy
We have a shed-type sunroom attached to the back of our home. There’s no way to seal the top plates since we can’t get to them because of the ceiling. Do you have any suggestions for sealing any leaks? We did seal around the ceiling lights because we felt air escaping. Would it help to seal around the top of each wall on the inside and the ceiling? The room is all shiplap including the ceiling. Great video - we will definitely be applying your techniques in the remainder of our home.
Thanks for the compliment! Air sealing the lights in the ceiling would have been super helpful. If there are gaps between the shiplap that can be caulked that would be the next step. Also caulk around any baseboard or crown molding on the ceiling where air could be escaping. Last would be getting the switch and outlets boxes sealed. The foam inserts would be the easiest thing there. Hope this helps!
Andy
Great work on this video!
Thank you!
Awesome video! Thank you for the information
Glad it was helpful!
I am insulating and airsealing my attic a little at a time during the cool months in the hot and humid Texas gulfcoast. I have a bulkhead that I plan to fill with dense packed cellulose, cap with foamboard, and then air seal. Do I put the foil side up or down? Also, I have a cathedral wall in the attic. I want to fill the 2x4 wall with batts and then cover with foamboard, but I don't know what kind of foamboard to use with the faced fiberglass batts.(I don't want to trap moisture.) I see where you used house wrap, but I would only need a small amount to do the job which is why I would prefer to use foamboard. TIA
Hi there, in your application I don't think it will matter much which side is facing outward to be honest. When we use foamboard to cover exposed walls in attics we face the foil side outward toward the roof because it then acts as a radiant barrier and reflects heat back toward the roof. In your situation it sounds like it will be covered with insulation on both sides? For the cathedral I would attempt to use 2" thick polyiso board. That will give you an R-Value of about R-13 and will likely not allow the inner surface to get cold enough to allow water vapor to condense on it. That's the theory anyway. Hope this helps!
Andy
Is this the case even with super old homes? (1920's midwest worker home) Our bathroom never had an exhaust fan installed, so I just got that done before the cold snap came through, but we still have frost on the underside of the roof. Worried that sealing things up will lead to mold growth on the underside of our ceiling by not allowing the higher humidity in our home to vent into the attic. I guess we need to lower our humidity throughout the house, but that's a bit difficult to do when the wife suffers from sleep apnea and benefits from a humidifier when we sleep.
Yes, all homes that have attics have air leaks hidden everywhere in them. Nice work getting the bathroom vent in. Did you vent that to the outside through the roof or gable wall? You shouldn't get mold growth on your inside walls / ceiling unless there is missing insulation in an area. Those areas can get cold and water can condense there with eventual mold growth. If you can air seal the attic floor, you will have naturally higher humidity inside the home because you're not constantly losing warm air and water vapor from inside the home to the attic.
Andy
Great information about the air sealing.
Hey there Andy, thank you!
Well done and informative.
Thanks Jack!
Andy
Hey Andy! Any suggestion for air sealing around canless recessed lights under the insulation?
Canless...so you mean like the flatter, pancake style LED lights? If so, what we do is use 1/2" thick foam insulation board (both polyiso and XPS board work well). We cut it and shape it so that there is a 4" clearance between the light and the sides of the box. Even though LED's should not create much heat, we still want to have a bit of leeway so that too much heat cannot build up. You can them seal it to the attic floor with foam sealant, or even tape together using metallic hvac tape in a pinch. But at some point you want to use foam sealant to seal and anchor it to the attic floor. Over time tapes will often become unreliable. You could also seal it to the ceiling from below by caulking around the perimeter. Hope this helps!
Andy
Awesome, thank you for this!!
You're welcome, hope it helps!
Andy
3:36 great Jedi reflexes, camera person!
We only hire the best Jedi's here ; )
I bought my multi level (1960) back in 2011 here in Pittsburgh. At the closing the son of the original owners said to me that his mom could never get warm in the house. The air leaks I found over the years and sealed I can understand why the poor woman was always cold in the winter. Most of the leaks were caused by the builder and other contractors who worked on the house over the years. It was bad folks the amount of various air leaks went from minor to major were plentiful. The worst area in the house that I thought was going to be an hour to an hour and half job was air sealing the garage and the stairwell up to the next level. That section alone was a seven to eight hour experience. I'd find one leak, look up, right, left or behind me and find another one. I really hate the builder and anyone that drilled and made holes in that part of the house. They'd cut a hole then just stuff insulation into it instead of fixing it right. Drill a hole and run a wire but not seal up the hole around the wire.
If you have the time to do it yourself, plan on spending a lot of time over a number of weeks if you have an older home. It's not an expensive job, your looking at $100 to maybe $300 in supplies and tools to do it yourself but expect to rack up a whole lot of hours. It's not so much sealing the leaks, it's spending the time hunting them down, then finding a solution to seal it up.
If time is not on your side because of family, work, age, hire someone to properly air seal your home you'll be glad you did. Plus most states and or power companies, offer generous rebates to home owners that have a certified energy efficiency companies seal and insulate their homes.
Hey there thanks for the comment. We call them stairwell voids and in this video you can see what it looks like after we have sealed a huge one. The air leaks alone can make a house extremely expensive and also difficult to heat and cool.
@@insulwiseenergycomfortsolu3293The stairs coming out of the garage have the stairs going to third level above them. Cold air in the garage could have easily seeped under those interior upper level stairs. The ceiling above the upper steps is flat, no drop area in the attic. Sealing the gap of the drywall ceiling in the garage where it meets the cinder block walls also made a big change. Think about an 1/32 inch gap, that runs the perimeter of a garage, that's 25 ft x 23 ft. It quickly adds up to a major opening to outside air. The other big change with sealing the garage and that stairwell was an almost total elimination of creepy crawly things inside my home.
I’ve noticed a building science trend where builders are favoring air sealing the rafters and making the attic into conditioned, air-sealed space. Matt Risinger from the Build show seems to talk a lot about it from the new home building perspective, but I’d imagine that level of effort may be even more challenging to get the right level of insulation in the attic.
You are correct, and I've seen that video. I believe that a MASSIVE issue that he leaves out is the type of foam that should absolutely be used if you insulate the underside of the roof. In his video I am almost positive that he used open cell foam, which is no no because it does not create a vapor barrier. That means water vapor can move through it and get trapped against the underside of your wooden roof. You DO NOT want this potential.
The "hot roof" solution can work well, but it should only be done if you are going to use closed cell foam. Closed cell foam is much more expensive, but at 2" thickness creates an effective moisture barrier (last time I checked). We have seen roof rot issues in Pittsburgh from using open cell foam to insulate the underside of roofs. If you google this and sniff around on the web a bit, you can verify this quickly.
Thanks!
Andy
He used open cell because he's in Texas where I think they want it to breathe
One major issue that makes it cost-prohibitive to retro fit from a ventilated attic is if you have a conventional gas furnace in the attic space, which is typical in homes without basements. That would have to be replaced with a heat-pump, or would have to have the gas furnace moved elsewhere.
Great video. I recently had someone look at my attic’s insulation and I asked about air sealing. The rep told me I did not need it bc of the climate in TN. After watching your video, I know that isn’t true.
Thanks! Yes, don't hire this company. Look for a company that's building science based (BPI or RESNET training). Anyone that tells you that an attic does not need air sealed is ignorant of these processes. I have felt air conditioning blasting my hands through attic air leaks on hot summer days Many times. Even if the air isn't rising from winter time stack effect, it can still escape via imbalances in duct systems.
Andy
Great video, and I wish I'd watched this video before choosing an insulation company last year. They did not go through these steps and properly sealed any air gaps and blew all the insulation in. I saw you drawing the map of lights and fire alarms and etc, but if the insulation is already blew in, how could anyone properly identify and seal those gaps with those foams? Thanks for your advice.
Well, it’s a shame they didn’t air seal the attic first, but that is unfortunately quite common. It is still possible, but not easy. Our teams at Insulwise do it everyday, but it takes some training, patience, planning (as in mapping out the air leaks), and also a willingness to get dirty. It is also more dangerous as the floor joists are obscured. You’d need a headlamp, knee pads, minimum N95 respirator, foam, a willingness to get dirty and a bit uncomfortable for several hours, and some persistence. But it is possible!
Andy
Thank you for your reply. That’s what I thought but was wondering if there was any trick. Know any highly recommended experienced technician around Seattle area? Just trying my luck.
good luck finding you wiring ceiling boxes . looks like a great job.thank you
Good to point that out. For customers that expected to do wiring work later we have hung flags from the roof rafters to indicate where they were located. Otherwise it's going to take a bit more time.
Thanks!
Andy
THNXS!!
You're welcome! Thanks for the shout out.
Andy
When you have insulated flex ductwork in the attic that “spiders” off of the main trunk, does it get buried underneath the blown in insulation? I don’t have any experience with the blown insulation and wondered if there was a risk of it collapsing the flex duct if it was buried?
Hi there, best approach for dealing with flex duct in an attic is to make sure that you've first sealed the connections to the trunk line / main trunk as tightly as you can. We see collars / take offs poorly attached and leaking massively all the time. You also need to seal the register boots to the attic floor with foam. Once you've been able to get the duct connections air sealed, then yes, you want to cover / encapsulate the flex lines with blown insulation to add extra R-Value. It will not collapse flex duct lines.
Andy
Some questions - should a homeowner consider insulating the ceiling of the attic. I see in the video you left it uninsulated. Is that the norm? Is there a benefit to insulating it?
Or, maybe that would only be done if the floor of the attic is covered in board (eg plywood) if the homeowner wants to use it to store boxes (christmas lights and the like)?
Hi there, the only time it could be recommended to insulate the underside of the roof deck is if the home has an extensive HVAC system in the attic. And if you do that you NEED to use closed cell foam (because it has a vapor barrier) and closed cell foam is very expensive. We believe in the vast majority of the time there is more risk and added expense than benefit to insulating the underside of the roof. When homeowners want to use the attic for storage we build them raised storage platforms. We have another video that shows that process if you're interested.
Thanks!
Andy
would one expect new construction homes to air seal liek you?
Unfortunately almost never, unless it was built as an energy star home and tested with a blower door when finished. Usually if they do anything they will hit the wire holes and plumbing pipe penetrations. The top plates and lots of other misc leaks are almost never sealed.
Would you mind specifying the name brand / model number of the orange foam you were using? I live in Louisiana. I want to air seal my attic - a little at a time - just methodically work my way through it. Then I want to staple radiant barrier Mylar to the upper roof rafters to reflect heat OUT. Finally I want to get someone to come blow in cellulose all over the give me a nice warm blanket.
Also - do you have a video that shows how you check/seal air leaks in existing duct work for A/C that’s in the attic space?
Also - last question - most all my plumbing up there is PEX. Do you recommend that I sleeve all of that as I uncover and find it?
I like what you do. I’m an old engineer and I understand the value of air sealing. What BUGS me is why the hell don’t the damn builders do this BEFORE they insulate? It’s like they are skipping a huge step and honestly they could market themselves as doing it when others don’t/wont!
In this video I used a great stuff foam gun and regular great stuff foam. That said, using regular $4-5 a can great stuff with the plastic straw works just as well, it just takes a bit longer to cure. The cheaper cans can also be more readily maneuvered into tight situations than the gun foam cans as well.
Andy
Can't imagine how long this takes in the attics of some older homes. I renovated my grandfathers old home that was built in the 50s and the attic gets very hot. Seems like you'd pay an arm and a leg for the amount of time it would take to go through that entire attic and do this... I wanted to install some solar fans but read if the attic isn't properly sealed it can actually suck cool air out of your home?
Hi, if you're doing it solo than yes and it's going to take some time, but if you draw a map you can isolate the attic into quadrants and do it one section at a time. It is also true that power roof fans can depressurize an attic and pull the AC from the house or heat (if they're also equipped with humidistats for the winter). Best practice is to thoroughly air seal the attic floor, then get the roof properly ventilated, and then insulate the attic floor to an R-49 level (we prefer cellulose insulation).
Andy
How to walk through those blown-in cellulose if I need to checkout any roof leak damage? What if minor roof water leak, how to handle the wet cellulose ?
Hey there good questions. If you need to get through it I'd recommend getting knee pads, a dust mask, and a head lamp. You want your hands to be free in an attic. You will need to use your feet to feel for the floor joists while using your hands to hold onto the roof rafters for support. After you have looked at the area you can brush the cellulose back into place with your feet, hands, or a broom. It's easy to do. But --- BE careful. We are practiced at doing this, but novices can fall through their ceiling if they're not careful. Also, the cellulose should be fine. Here is a link to a video that I took that shows what happens to cellulose after a roof leak. It's fine so long as it can dry out.
ua-cam.com/video/2XQK-Ba1hWc/v-deo.html&pp=ygUXaW5zdWx3aXNlIHdldCBjZWxsdWxvc2U%3D
Andy
Great video I learned a lot.
Hi Jack, I'm glad this helped you out!
Andy
Great work what’s the foam gun set up your using and where can I find it ?
Hi there, the foam gun that I use in the video is a basic Great Stuff foam gun that can be purchased in most Home Depot or Lowe's stores. However, we also often use the basic off-the-shelf cans of Great Stuff that go for about $5. The flexible plastic straws and smaller can size allow us to more easily air seal the air leaks that we find that are in tighter spaces. That stuff works just as well, just without the fancy gun. The guns like I use in the video also need to be cleaned after they're used or they clog up.
Hope this helps!
Andy
Don’t you want to spray foam the rafters for the roof, add vent channels and batt insulation and/or a radiant barrier?
You can do it this way too IF you are going to use closed cell foam. Many foam contractors will use open cell foam for this, which is a no no (can contribute to / cause your roof to rot and we have seen this happen in Pittsburgh). However, closed cell foam is very expensive, so most homeowners do not want to pay for this. In fact most foam contractors don't even bring it up. Our philosophy is to allow the roof to operate independently of the air and thermal barrier at the top of the home. When done correctly, this is far less expensive than using closed cell foam, far safer for your roof than using open cell foam, and a highly effective and economical solution.
Andy
Wow. That's well-insulated.
We certainly try!
Did you put baffles in for ventilation?
Hi there, good question. In this case we did not because this home did not have existing soffit ventilation. The gutters are hung literally on the tops of the exterior walls at the edge of the roof. That said, attics ALWAYS should have both intake and exhaust ventilation (but well sized gable vents on homes that have somewhat of an east/ west alignment to catch the breeze also tend to do extremely well). At this home we installed 4 slant back vents just above the insulation layer. You can see light pouring through some of them as I pan across across the back portion of the attic / home.
Thanks,
Andy
Good information,thank you!
Glad you found it helpful!
Very informative video. Great stuff! (pun intended) Why do you recommend foam versus polyurethane caulk for sealing the air penetrations?
Thanks! Polyurethane caulk would work just fine in some cases. The reason we like foam is because it is far less expensive, expands to seal all kinds of varied penetrations, can fill voids as wide as 4-6" inches when you learn how to use it correctly, the can and straw can fit into LOTS of tight and difficult to reach areas, like plumbing penetrations that are close to the edges of roof decks, etc, and the cans don't freeze. I've had tubes of caulk freeze in the back of a truck and then become unusable. Cans of Great Stuff can sit in a truck at 0 degrees for weeks, then after running some hot water over them they're ready to go.
Hope this helps!
Andy
Blower door test with no climate Folie sealed properly before you put the Gipsum board there? It’s useless….
Great video thanks!
Thanks, glad to be able to help!
How about a vapour barrier sheet spread across the attic. Is wood permeable?
Wood is permeable, but drywall with a few layers of paint on it is generally a "pretty decent" vapor barrier. Think of your bathroom ceiling after taking a hot steamy shower if you haven't turned on a fan, it will be dripping. We seal the penetrations, and then make sure the roof is properly ventilated. If both of these measures are done correctly, it is exceptionally rare to later have a problem with excessive moisture or mold in an attic space.
Andy
Great video. very educational
Thank you Jordan, we certainly try!
Andy
I have blown in cellulose thats about 12 inches, i went into my attic to air seal and it was impossible , too much cellulose. I ended up finding the pvc vent protrusions and sealed the holes that they came up theough and then called it a day lol.
Will it be beneficial to seal everything from inside the home instead? I did all outlets and a few lights.
Hey there, yes it is definitely a chore to air seal when blown in cellulose is present, especially when there is a lot of it. We do have to deal with this from time to time here. And it would be this type of situation where drawing a map of the air leaks before going into the attic would be most helpful. It's just too difficult to find them all otherwise. What we do is standard knee pads, gloves, headlamps, and respirator, and then move methodically through it, sealing as you go. You will be covered in cellulose as you move it out of the way. Your whole attic look like a series of lumps and piles when you're done. At that point we would move back through it and use something like a house hold broom to "swoosh" it back into place so that it's even. Air sealing an attic that is already blown with cellulose is definitely not for the faint of heart.
I think it would be nearly impossible to do a good job air sealing from the inside once the house has been finished. You would never be able to get the top plates, wire holes, around bath fans, junction boxes, etc. There are types of recessed lights that can be sealed from the inside, but my guess is that you'd miss 90-95% of the penetrations in the attic floor. That said, I give you credit for trying!
Andy
Can you use any foam or does it have to be fire blocking?
We often just use regular Great Stuff for $5 a can. It does just as good of a job and is much less expensive. If your house has a fire, and won't be the type of foam that you used for attic air sealing that makes or breaks the damage the fire does.
@@insulwiseenergycomfortsolu3293 thanks for tip. Like your videos. I gotta say, you guys earn your keep! I am about sick of doing my own attic. I used to say if I went into a trade instead of a desk job I would have done HVAC. I recant my earlier statement after crawling around in our attic for several days. Lol
It sounds like there weren’t soffit vents in this attic, what would you recommend doing to prevent blocking the soffit vents when you blow in the cellulose?
There was zero overhang on this house. If you had an overhang but no soffit vents, we would first stuff / block the overhang with fiberglass and then install roof ventilation in order to get the attic properly ventilated.
Andy
What are your thoughts on using a thermal adapter like the Flir or Seek devices to map real time heat loss?
Not a bad idea at all. If you add in a running blower door it gets even clearer. However, if you simply assume that every penetration in the attic floor that you find is an air leak (top plate, wire hole, plumbing stack pipe, gaps around bath fans, recessed lights, etc), and seal it with foam, you should have the same outcome. You're not going to get measurable air leakage through solid drywall, plaster, or framing lumber.
Andy
@@insulwiseenergycomfortsolu3293 Like others, my rafter bays are not blocked so air will flow from soffit to soffit in this cape cod's upper floor. You can really see it with the thermal. Now I'm just trying to figure out which foam gun will work best. Looks like the Great Stuff Pro14 has the least offenses.
thanks for video
Glad that you found it helpful!
All of my walls running north to south seem to have have top plates, which I believe to be on top of the gaps in the walls. There seems to be no visible gap between the plates and the drywall below it. Should I still be adding spray foam along the sides of these? I tried a few times to see what would happen, but the foam kinda just goes everywhere even when spraying it slowly.
East to west walls seem to be normal and I am finding the gaps/wires/other holes fine and filling them. Maybe it is just the way the construction was done, the building was made in 1960 and I know plaster was used a lot for walls and ceilings back then.
Hi there, we seal the plates regardless of the appearance of the plates in terms of visible gaps or no visible gaps. It's just a matter of habit and keeps our teams from trying to make that judgement. But if you're having difficulty getting the foam to lay where you want it to, you might not be able to do it. It doesn't sound like the plates in question are big leakers though so you may ok not doing them. Hope this helps!
Andy
Thanks for the reply. I am actually really glad I came across this channel. There are many tips which I never found elsewhere (like the dust lines under the insulation).
Do you have any tips for finding sections of the attic, which have no insulation under the top sheets?. While air sealing I have noticed some sections of the attic seem to have no insulation above the ceiling except a sheet of insulation, which is laying across the beams. Is the only way to really find all of them to pull back every sheet and lock? This wouldn't be a huge problem to do while putting up the baffles, but I was hopeful there was a better way.
@@insulwiseenergycomfortsolu3293
@@xSatansGiftx Hi there and thank you! I'm not sure what you mean by sheets of insulation. Do you mean pink batts of fiberglass are laying across the studs? Sheets of foam board? Usually the ceiling fixtures, light switches, bulk heads, walls, etc give you a strong idea for where most of your air leaks will be from below. The ones you can't see from below are plumbing stack pipes that run up through the walls. But if you don't have a bathroom or kitchen in the vicinity of that area, you are likely to not have a plumbing pipe running up through a top plate there. Let me know about the sheets of insulation.
Andy
Yes I mean the batts of insulation. In my attic there is some sort of older yellow fiber glass that looks like big cotton balls and the batts laying over top of this. I have noticed while air sealing, that some areas under the batts do not have this yellow insulation and I can see the bare ceiling (after pulling back the batts).
I was just hoping you possibly knew a good way to find these spots without moving back every sheet to see the places missing insulation. I am going to be putting in blown in insulation and I am going to try and fill these empty areas under the batts.
If the best solution is just to move every batt and look under it, I will just do that. I was just hoping there was some easy way to find these bare ceiling areas.
Thanks for the reply again.@@insulwiseenergycomfortsolu3293
No baffles added?
How about the perimeter? The exterior wall top plates. With such a low pitch roof. How did u reach there and get it sealed?
Hi Dan, good observation. We didn't install ventilation baffles because this home did not have any soffit vents or intake ventilation of any kind. We added intake ventilation in the form of a series of slant back vents that we installed just above the insulation line on the back of the home. You can see some of these in the last segment of the video. We sealed the exterior side-wall top plates, but not the front or back exterior top plates due to the low slope. We sometimes offer to spray foam these difficult to reach top plates with two part foam, but due to the significant added cost we only recommend doing this in certain critical situations. That said, all of the exterior walls in this home were insulated with fiberglass batts. The presence of these batts does a decent, but not perfect job of knocking down air flow through them, so we didn't recommend the added expense of spray foaming them with two part foam.
Hope this helps!
Andy
Nice job
Thanks!
at 11:00, what is the light that appears to be coming from a hole in the roof?
This attic had zero intake ventilation. We needed to install it in order to balance the ridge vent (exhaust ventilation). We did this by installing a series of slant back vents along the back of the house. That is the light that you see coming through.
Andy
I don't see any chimneys... But what if there was a wood burning fireplace flue penetration? Yiu aren't supposed to be within two inches of the flue... So how can air leaks be prevented there?
You CAN seal around hot flues and chimneys, but it requires a specific process. We cut sheet metal to conform around or butt against the flue or chimney, and then seal the sheet metal to the flue or chimney using HTV (high temperature) silicone. We then wrap either a fiberglass or rock wool batt around the flue pipe or chimney before blowing in cellulose insulation around the area. The main thing is using something to air seal that either cannot combust (sheet metal) or is designed for high heat applications (htv silicone). Hope this helps!
Andy
My attic has 6-8 in. of cellulose. Will put more because I noticed when I turn heater on then off my hear escapes a couple minutes later. Should a crawl space also be insulated? Thank you! Any tips recommended
Hi there sorry for the delay. Before you add insulation to an attic you first want to air seal it like we do in this video. But yes, doing both air sealing and insulation work will definitely help the heat to stay in your home more efficiently. Most crawl spaces should be encapsulated. That means insulating and air sealing the walls and then installing a vapor barrier on the ground.
Andy
9:56 Are the soffits dammed by batt?? or did they have a ridge vent and get baffles?
This house had no soffit vents, the gutter was hung directly on the exterior wall (there was no overhang). We installed slant back vents on the back of the home to provide a means for intake ventilation. You can see light shining through from some of them at the end of the video.
Andy
@@insulwiseenergycomfortsolu3293 wow ok nice, great work....really love the ceiling map idea too
How do you typically air seal when a home has a vertical cavity that is for air ducts to travel around?
If there are air ducts that come up from the house and into the attic, we seal around the ducts with 1/2" foam board and then foam sealant, but any solid material can be used like plywood or even heavy cardboard in a pinch. The goal is to eliminate any way for air from inside the home to communicate with or transfer to the attic.
Andy
I'm assuming that you have to pull and leave the insulation off the exposed top plates to allow the foam to cure and dry? How long do you usually wait before placing the insulation back over the areas where you sealed the top plates?
You can do that and it may be better in some cases, but we do is inject the foam down into the top plate cracks, wire holes, plumbing penetrations, etc. That way if the batt falls back onto the area that you've just air sealed, it's far less likely to push the foam off of the air leak.
Andy
Most foams harden within minutes
@@ajamesc55 My experience has been that foams used from guns like the one shown in our video harden / cure within minutes, but the cheaper foams like Great Stuff for $4-5 a can can take 30-60 minutes to cure depending on temperature. The cheap stuff works just as well, you just have to be a bit more cognizant of not smearing it until it cures.
Andy
I might have missed it if you mentioned it, but if there is pre-existing cellulose in an attic, does that need to be removed before air sealing top plates? Can it impact curing if insulation goes back over wet foam?
Hi Joe, you can definitely air seal if there is pre-existing cellulose insulation present. However, it is considerably more time consuming and less fun. Depending on how much is present, it can be a bit like pushing sand around at the beach where you move some, and then it falls back down into the area you were attempting to move it from. You just have to patient with it, organized, draw a good map from below so that you know where and what you're looking for, be methodical, and lastly double check your work --- even if you did it yourself. If a bit of insulation gets onto the foam it won't affect the curing. But if you completely swipe away the bead of foam with your glove or foot, that's a different matter. We air seal attics that are insulated with varying degrees of cellulose fairly often.
Hope this helps!
Andy
@@insulwiseenergycomfortsolu3293 Thanks for the quick reply! That's good to know, we had a company air seal our attic, add soffit vents/baffles, and add more insulation on top of our existing cellulose. But recently had a blower door test with thermal imaging and it looks like top plate spots were missed or the sealant didn't cure, so trying to get an idea of what's common practice.
@@joelalonde In our area, many of our competitors say that they "air seal." They don't (or at best they do a totally lamo job doing it). Air sealing an attic is difficult, tedious work and lots of companies 1) aren't truly committed to it 2) don't have staff that fully understand how to do it 3) don't want to pay the added expense of time and materials for doing it right, etc. Now, there are some places where we can't always effectively seal top plates, like exterior walls of a low sloping roof. But all of the other places we make a serious effort to get to. However -- it is easy to check to see if they hit the plates or not. If you put your hand down through the cellulose where the top plates, bathroom fans, plumbing stack pipes, etc are, you will either feel a bead of foam on the thing in question --- or you will not. If you don't feel a semi-hard bead of foam -- it didn't get sealed.
Andy
@@insulwiseenergycomfortsolu3293 Appreciate the details, thank you
What would it cost to remove old insulation, do pest control spray, air seal all openings, and install sealant and do r38 or R49 insulation on 3K sq. ft. area?
Every house is different, even with the specifications that you provided. If you are in the Pittsburgh area just give us a call and we'll happily come out and quote your project free of charge.
Thanks!
What kind of pricing does something like this cost
@insulwiseenergycomfortsolu3293
7 hours ago
It's tough for me to give an exact figure because every attic is different, even homes in plans that are next door to each other. We generally charge about $1 per sq ft for air sealing, and then extra for large items like stair well voids, bulkheads (dropped ceiling areas), recessed lights, etc. We then charge an additional amount for adding in the extra cellulose insulation at the end, and that depends on how many inches we need to blow in to finish with a combined R-49 insulation level (generally about 15" inches total).
Hope this helps!
Andy
Is it cold there? I live in Fl and have never experienced being in an attic without being covered in sweat.
It certainly gets cold here during the winter, but we work in attics year round. There is definitely an adjustment phase to dealing with the heat!
Andy
Where the shower bulk heads and stairs were sealed seems like the moisture would get trapped in the pockets. Have you ever been back to one years later? Especially the bathroom ones.
Hi, there's only a problem with moisture and water vapor if there is a surface present that gets cold enough for water vapor to condense. If this happens mold can start to grow. However, these "pockets" are fully within the conditioned space of the home, and there is a full layer of insulation on top of them. So there is no issue. These are common ways for air sealing cavities in floors of attics. We've been utilizing these same solutions for 15 years in thousands of homes, there's no issues.
Thanks,
Andy
I havent seen anyone address what happens with balloon framed houses. Ours is 1915 vintage. Had insufficient blown in, needed to remove knob and tube wiring. Debating the best way to plug off openings down into wall stud bays. I'm guessing having blown in cellulose go in, then some sort of plug? Costs matter
Hi, we encounter this type of home a few times every year. Definitely have the knob and tube wiring removed first. We insist on that being done in the homes that we work in. But, if you find a team that can effectively dense pack cellulose insulation, you first want to 1) plug the bottoms of the stud bays in the basement and then 2) use a fill tube and push it as far down the bays as you can and then dense pack the cellulose insulation into the vertical stud bays.
If the team has the right gear and technique, they will be able to hit somewhere between 1/2- 1/3 of the exterior walls this way. We would still drill the entire first floor and beneath the windows. You can cap the tops of the stud bays with foam board and foam sealant if you want. But if the bays have been properly dense packed with cellulose, there will be no air or heat coming up through them once this has been done. Hope this helps!
Andy
@@insulwiseenergycomfortsolu3293 thanks so much for responding. I just finished having the remainder of k&t removed. While clearing for their work, I realized I shouldn't ignore some of the attic issues much longer
@@insulwiseenergycomfortsolu3293 I also have been blocking and sealing from the basement, and am about 2/3 way around the perimeter. So much to do, so little time
@@SEaudiofan You're welcome, and this would be perfect timing for you to remedy the issues going on up there.
My question is why? What difference does it make if the cracks are sealed, if it all sits under R60? A little air crack is going to work its way through R60?
Hi Eddie, the answer is yes. Air flow from your house during the winter will absolutely bleed through any type of blown in insulation -- unless it's dense packed but that's a closed cavity solution. We prove this by doing blower door tests in homes with tons of blown in fiberglass (and sometimes even cellulose) all the time.
brilliant
Thank you!
What if your attic already has installation already blown in?
It's harder but it's the same steps. Draw your map from below, put on your PPE gear, then crawl through the material as carefully as possible to track down the air leaks and seal them. It will suck at first, but you get used to it after a few minutes. You just need to be methodical and not in a hurry.
hi can i put fiberglass rolls over existing blown in cellouse from years ago (settled)that was blown over fiberglass insulation from when the house was built in 1957
You could, but --- the reason that we are not proponents of using batt fiberglass in attics is because it's almost impossible to get the batts to conform around all of the miscellaneous obstructions that are located on the attic floor (plumbing stack pipes, wires, bath fans, recessed lights, the roof rafters at the edge of the roof) and you wind up with lots of gaps. I'll attach a link to my site and you can see some pics to see what I mean. That said, I would do the best that I could with fiberglass batts before I used blown fiberglass. But best choice, at least as we see it, is to use blown in cellulose insulation.
Good luck to you!
Andy
Did this home not have soffits along the underside of the gutter that vent up to a roof vent?? It looks like the insulation was blown into those areas?
No, this home did not have any soffit vents whatsoever. We installed a series of slant back vents along the back of the roof to provide intake ventilation. You can see the light coming in from one of them in the final part of the video.
Andy
@@insulwiseenergycomfortsolu3293 Thanks for the clarification!
Well done!
Thank you!
Best foam to use?
Most of the foams are really pretty similar, we like regular Great Stuff for about $5k a can. The biggest difference is that it takes longer to cure than the more expensive foams so it can be messier until you get used to using it. But for an attic application all of them do pretty much the same thing.
@ 6:56 shouldnt you have just insulated down in there instead of doing what you did?
Hi, not in this case. If you insulate the stairwell side walls and sloped ceiling you have FAR more area that is exposed to hot and cold temps, versus making it a flat plane on the top. So this method will allow for better energy efficiency. However, when stairwell voids like this abut exterior walls of homes, we do fill them in with cellulose insulation as opposed to capping them. Hope this helps.
Andy
Were soffit vents installed? It didn't look like there were any.
This house had no soffit vents. We installed intake vents on the back of the house.
Great work! Curious what you charge per sq ft for jobs like these?
Thank you for the compliment! It's tough for me to give an exact figure because every attic is different, even homes in plans that are next door to each other. We generally charge about $1 per sq ft for air sealing, and then extra for large items like stair well voids, bulkheads (dropped ceiling areas), recessed lights, etc. We then charge an additional amount for adding in the extra cellulose insulation at the end, and that depends on how many inches we need to blow in to finish with a combined R-49 insulation level (generally about 15" inches total).
Hope this helps!
Andy
What does something like this cost?
The cost range is usually $3-6k depending on the attic size, existing insulation level, types and quantities of air leaks to be sealed, vents that may need to be installed, and how the attic hatch is to be addressed. The range varies widely. But if the work is done right, you will be instantly surprised and happy with the effect.
What about baffles?
This roof did not have any kind of soffit or perimeter ventilation.
Did you remove the old insulation before blowing in the new one?
We did not, We map out the air leaks, seal them, and utilize the existing insulation that is there. It makes the project less expensive for the homeowner.
@@insulwiseenergycomfortsolu3293 thank you.
What about soffit venting? I don't see a thermal break at roof and I don't see vent baffles.
Read previous replies to this question, I address that several times. Thanks!
@@insulwiseenergycomfortsolu3293 Ok, I didn't read all of the replies. You explained what you did in this case. I'm trying to determine if I need to ventilate my soffits and then move back my insulation and install baffles in my attic, OR if it is MEANT to be this way for some valid reason and I should leave it alone. This house was built like this in 1978. It does have three vents near the ridge, but the soffits are all sealed up and there is insulation pushed out to the roofline. I'm in South Central Kansas, "Zone 4." We have brutally hot summers with humidity, and brutally cold winters. Both summer and winter can be VERY windy.
@@dolfinwriter5389 Ahhh ok I totally understand. Yes -- if you have an unconditioned, vented attic like you have and the one in this video -- you absolutely want to 1) Have an adequate amount of roof ventilation and 2) make sure that that ventilation is balanced between intake (soffit vents) and exhaust (ridge ventilation). If you do not, the ridge vents have a tendency to exacerbate Stack Effect within the home during winter. This leads to added heat loss and increased risk of attic mold growth as additional water vapor from your home via attic floor air leakage gets deposited into your attic.
However -- soffit vents DO increase the risk for a roof getting blown off in a high wind storm event. There is a good argument to be made for using closed cell spray foam (NOT open cell foam. Two entirely different materials) to insulate the underside of the roof in areas like this. It will not only insulate extremely well and also provide a vapor barrier --- but it will increase the structural rigidity of the roof --- and not leave soffit vents as a place where powerful gusts can enter and potentially lift the roof off. However, closed cell spray foam tends to be very expensive. If I were you and had an extra $15-25k sitting around this just might be the direction that I would go. Otherwise, you should find a way to install intake ventilation to balance your exhaust vents.
At the home in this video we installed a series of slant back vents along the back of the home, about 4. It's not as good as continuous soffit ventilation or continuous under-shingle intake vents, but it far better than not installing them. After air sealing the attic floor, the exhaust vents will now pull their air from these slant back vents as opposed to the house. This helps to dry the attic from unanticipated moisture intrusion, and dissipate summer heat. You can see light coming in from some of them in the final part of the video.
Hope this helps!
Andy
Idiots that built my house in 1979, bought home in 2006.. dryer vented to crawl space, and upstairs bathroom vented to attic, downstairs bathroom vented to sofet. I had to re vent for it to go all outside.
We see this all the time. Nice work identifying the issues and correcting them. Some people don't realize these problems until these areas begin rotting from mold growth.
Hey how can I hire you
Thanks for the compliment, but for the time being we only work out of the Pittsburgh, Pa area.
Andy
I’m skeptical that sealing every linear inch of the drywall corners is necessary. They’re already taped and sealed on the finish side. But the penetrations definitely need to get sealed.
Hi Tommy, what happens is that the drywall pulls away from the top plates, typically after the studs have shrank a bit from their original moisture percentage going down as they dry out. We have blower door tested these top plate leaks plenty of times, they definitely leak. On this other video here that I took from a home built in the 1990's you can see the black streaks running through the fiberglass immediately over top of the top plates. That is from warm air from the house passing through them and the dust in the air getting trapped in the fiberglass. As there is typically a 1/8" gap or larger on either side of the top plate, when added together the combined air leakage in attics from leaky top plates is typically substantial. Sealing top plates should be a major priority for anyone doing attic air sealing work.
Link to top plate air leakage visual proof:
ua-cam.com/video/X7GMG3T8cE8/v-deo.html&pp=ygUrYWlyIHNlYWwgYW4gYXR0aWMgdGhhdCBpcyBhbHJlYWR5IGluc3VsYXRlZA%3D%3D
Hope this helps.
Andy
If you already have R60 blown in insulation, how do you even start to do air sealing after the fact without ruining the R60 blanket and having to re-blow insulation
We have had to air seal attics that have already been blown in with a lot of material, typically blown in fiberglass. You have to displace it as you go, double check that you have in fact hit everything, and then rake it back into place. Cellulose is more difficult to displace, it acts like sand on a beach. But blown fiberglass is actually quite easy. The only drawback with blown fiberglass is that it can compact a good bit while doing this. When we retrofit attics, we always air seal them first, and then blow a fresh blanket of cellulose on top of whatever was there to get it 100% even again. But a homeowner likely would not need to get it that "perfect."
@@insulwiseenergycomfortsolu3293 I just had my attic redone this spring to R60 with blown in fibreglass. Before that I airsealed all I could think of myself, any light fixture, and any wiring holes. Thankfully there are no exhaust fans up there since I have a central exhaust system out the side of my house. But I am also not an expert at it either, so I assume I missed something. Having a energy audit done to get in with some govt grant, I have taken my house from 139 GJ of energy a year to 101 GJ a year, according to their before and after readings, and blower door test. So I must of done something right. But even so, I still have some attic frost (I check a few days into a cold snap when we get them) But I dont think its enough to accumulate into attic rain or anything, or if it does, its so light that it must dry out with ventilation. I have my head in my attic at least a half dozen times per year, just to check that things are ok. Would I like zero frost, 100%. But as well, when you have a low of -35 outside with sometimes relative humidity of 70%, that frost can stick to things inside your attic, just like hoar frost outside. Now that I would like to figure out how to mitigate.
doesn't prior mean before? So are you air sealing an attic before insulation? But the title says How to Air Seal That is Already Insulated. I'll view on...
Yes, it does. I had to try to convey in a short title that we were air sealing an attic that already had insulation in it. We are retrofitting the insulation in existing homes. Nearly all of them have insulation already in them.