Just re-did my roof. House was built in 1965 with less than a 2/12 roof pitch. Major ice damming for years. Pulled the old roof/plywood off and spray foamed to R-36 from the top onto the ceiling drywall leaving a 2" air space at top of rafters with plywood at ridge cut back 6" for ridge vent. Sheathed with plywood. Covered plywood with ice and water shield leaving ridge cavity open. Strapped plywood 1 1/2" air space with 1x4. Used standing seam metal roofing. I have venting within the cavity and a vented over roof. Custom soffit intake vent with a continuous Maximum ridge vent made from steel that resembles a tunnel on the ridge with two Maximum roof ventilators. Not only does the cavity itself vent but the underside of the steel has a constant air wash removing any condensation that may form from temperature fluctuations. We live in southern Ontario Canada. Not only have our heating and cooling bills been reduced but we no longer have any ice damming in @t yes spray foam does work and in this application it performs quite well. Ventilation is key. You can have an R-80 roof but if you do not have proper ventilation you will get ice damming and possibly condensation/moisture issues. Do the research and engineered properly spray from out performs batt insulation hands down. Just ask Mike Holmes what he thinks of spray foam.
I'm doing work on a 100 year old house. We gutted the inside and there is no dry rot or any kind of bug damage anywhere. It has wood shingles, tar paper and diagonal 1x6" wood sheathing. I think this says something for a structure where water can evaporate. Thanks for the video and your thoughts on the subject.
It says something for a structure where water can evaporate via massive amounts of air infiltration and massive amounts of fuel usage to heat the structure and keep the air dry. Moisture tends to cause damage to a house when you have the temerity to insulate things in order to reduce heat loss. An older house in winter is an enormous dehydrator, pulling in air with low absolute moisture and heating it up. The downsides are large amounts of fuel usage, and ice damming. If the roof is steep and well-sealed enough to avoid the ice dams, things can work fairly well. Air conditioning can also cause significant issues in warm climates.
@@TrogdorBurnin8or , I hear what you're saying, makes a lot of sense. I guess here in northern California, where the weather is mild, the heating losses are not as important as other parts of the country.
Good point by trogdor. The weather does make a big difference and I think this is why this foam product sounds so appealing. However, foam might be an excellent product for reducing airflow and lowering heating costs, but at what cost, especially if it leads to expensive home repairs in the future. By the way, there are thousands of homes like yours that are still doing just fine.
@@tomruth9487 I'm in south Texas and do it to keep heat out of attics. I use a rafter panel inside and then spray the foam right over it. Keeps the attic cooler because I have the air flow to let the heat (and moisture) out at the ridge vent. Amazon - Insulation Baffle for 24" Rafter Bays by SmartBaffle
Appreciate this video, Greg. I'm slow renovating a 115-year old two-flat house here in Chicago. It's evident the old owners, and owners before them, deferred maintenance and upkeep. The attic has zero insulation, its also the default mechanical room with the water heaters up there (one was made in 1994!) I've brought in insulation companies and they've all suggested open-cell spray foam. Which I'm not a fan of because ventilation/evaporation and fire melt point. I'm looking into mineral wool batts and all the companies I've had out are saying that's not a smart idea because of cost. Your video has confirmed my decision to go with mineral wool and Reflectix panels in the attic and crawl space (which is a whole different mess). Funny how the algorithm works. Thanks.
I've had the same thought s on this! I've decided on a metal roof and puting the 1in. Gap between the roof sheeting and foam yousing foil foam for the raident barrier. So i get much-needed air flow with any moisture being able to vent outside ! Now the floor has its owen challenges ! So i decided to youse till with water repellant grouting with a drain by the toilet area and bathtub area. Is it full proof well im hoping 90% and it will be someone else's problem when the 10% kicks in.
I did some looking into this a few years back when I was encapsulating my crawlspace. I found some research that suggested that moisture will transfer through the wood floor and floor joists and deposit and trap at the point between the wood and foam (warm moist air from above will form water when in contact with the cool crawl space). It also suggested that attaching a membrane / vapour barrier in the crawl space to the under side of the joists is bad.
I agree with practically everything you said and since waterproof vapor barriers can trap moisture, then it would make sense to avoid using them, especially on buildings made of wood.
@@gregvancom Would a Conditioned Crawl space and Attic with Vapor barrier in a crawlspace good thick water resistant underlayment on top of the roof sheathing fix all the water and moisture problems? Wouldn’t the instal a dehumidifier in both attic and condition basement help further? I understand the need to detect leaks from loose roof shingles, but isn't that up to the owner to be diligent by inspecting his own roof from time to time? Especially after a downpour? I guess the increased in R Value with CLOSED or OPEN spray foam as apposed to other types of insulation sacrifices leak detection.
I’ve been on several roofs with completely rotted plywood with absolutely no sign of leaking on the drywall of the interior of the house with both closed and open cell insulation. We will see huge problems in the near future with homes sprayed with foam and the roof dried in with peal-n-stick/ ice and water shield. Plywood has to breath if not it will dry rot and that’s what we will see a lot of in the next 10-15 years
What you are getting at is a totally valid point. Craftsmanship is almost never perfect. I think that this could really cause problems especially in the roof structure where water is most likely to penetrate. Being that closed cell foam wont let water leak through the structure, you would not notice a leak. Even with elevation creating some drainage the wood will still absorb some of that water. Very valid point, glad i watched this video. It will make me think that much deeper into the use of spray foam.
-- Foam allows water to seep/creep past it. This is an issue solved at the water/vapor control layer for the roof decking. If you're that worried, waterproof and edge/gap seal the primary roof deck. Set firring and lay down a secondary deck (which you also waterproof) if you're laying shingles/tile. For metal roofing, simply lay the roof on. -- Foam allows water retention in flooring. Planning issue. If you're inside a conditioned space, unless you're dealing with insane amounts of prolonged water exposure (the house is flooded out), most reasonable water exposure is set to dry to the interior. Sure, you might have to pop up decorative flooring if it's bad enough. But there are a few tile/wood flooring systems that allow you to pop up individual tiles/boards (or the whole floor if necessary) and let the floor dry out properly. And if are worried about the subfloor gapping, double-subfloor or tape the gaps.
@@gregvancomnot to sound lime a idiot but can you illustrate this on how this would work via video simulation? I'm interested and close to getting my attic spray foamed but want to truly get good honest Feedback before doing this!
I’ve been thinking the same thing.... well not EXACTLY the same. But close! Everyone has been telling me to do it but there hasn’t been enough time for it to give answers.
I totally agree and have a difficult time understanding why people are susceptible to anything that sounds like it will work, even when it doesn't or in this case can produce unnecessary home repairs in the future.
Its a class 1 fire retardant...ie if a piece of wood is burning it will burn. take the wood away it will extinguish itself....if it was so dangerous it wouldn't be used in fire walls and it is used in conjunction with fire retardant paint
Wrong, there is video proof that spray foam does not burn itself as there is nothing flammable about it. Maybe when the spray foam is being applied and curing then it would be flammable, but not once it has cured.
The issue of leak detection is a legitimate concern. Hopefully there is a foam product with a visual indicator, perhaps the foam could change color if it gets wet.
What are your thoughts on placing a baffle in between the trusses and the spraying the foam insulation. That way if there is a leak, the baffle will collect the water and the water will slide down and out. Thanks.
@@JosephClay How does adherence to the substrate prevent heat build up as opposed to placing a baffle between the substrate and spray foam? If you spray a layer of foam on the interior of the house you create a thermal break regardless if there is space between the foam and substrate. If anything the baffle would create airflow and if there ever was a roof leak it would allow the substrate to dry. In a climate with extreme fluctuating temperatures a vented over roof is recommend over even a spray foamed roof (hot roof). Joseph Lstiburek has the data to back this up.
@@jeffleicher3579 the only reason for airflow is the heat builds up enough. Turbines work properly when the heat builds up and causes airflow. Airflow is caused by heat build up. Not by air space
@@JosephClay I should have explained further. In addition to the baffle you would have an air intake at the bottom at the overhang and a ridge vent on top creating airflow between the baffle and substrate. In cold climates you have heat loss regardless of R-value which in turn could result in ice damming without ventilation in the roof whether it be a vented over roof or a vented attic space. In warm climates it dissipates heat. Turbines are often not good solution for airflow as they can create negative pressure in the attic space which in turn can suck cold or warm air from the the interior of the building envelope if it is not air sealed properly. (In a traditional attic space) Meaning higher heating or cooling costs and unbalanced ventilation. In addition should the roof ever fail and leak the air space would allow the substrate to dry. If you have spray foam on the underside of the substrate and then an ice and water shield you have essentially created a vapour lock within the roof system ....in a cathedral application... in which the rafters would become saturated with water and perhaps never dry because there is no ventilation.
@@jeffleicher3579I would love to hear more on how this works, love to see some kind of example or illustrate that shows how all this would work. I'm in process of getting ym attic CCSF installed on attic ceilings and want to be sure it's good all around idea!
Great great video just wish these individuals who comment would share some diagrams or pictures and or illustrations to better understand the argument. Not to say the argument is not valid as many of us are learning through this channel and hope these commentd with ideas suggestions or compelling arguments would have some demo's, illustrations similar to how your videos are setup with visual simulations super easy to understand and learn from!
If leack is minor moisture will be taken care with AC/ dehumidifier. Fiberglass on other hand will be completely ruined and ready for "creating new life".. mold. So no.. foam is not an issue
Let me see if I can make sense out of your statement, a minor leak with small amounts of moisture, might not be a problem, but bigger leaks could be, but it's okay to use foam, but what type of foam? Lotta loose ends in your comment. Feel free to remove it if you want to or provide us with more details.
I think what we're all trying to achieve is huge r-values but allowing all materials that can rot to breathe. . . I'm not sure anyone has got there with the spray foams. The open cell can pass water but the drying cycle is longer than the dry season in a lot of climates. Sure 150 year old homes show no sign of rot with very very low r-values which means energy bills that outweigh the cost of rebuilding every 50 years. It's a balancing act with our technology it seems. . . Live in a Ziploc bag and rot or live in a paper bag and swelter/freeze. Gotta be a middle.
Good points and I think what I'm trying to explain in this video is the fact that there are plenty of builders who for whatever reason have a difficult time figuring out the pros and cons of new products.
Exactly as long as spray foam been used, there should be a know fact. Like putting diesel in a gas engine or gasoline in the engine oil is bad and car deadly . But with foam it like I'll sell it to you but I don't have it in my home, or if I did use foam I'm gonna sell it and move let someone else buy the problem
You are supposed to add baffles and then the insulation. The baffles connect to the eaves and the vents in the eaves travel through the baffles to the ridge vent
none of the foam guys are bothering to do this. energy companies are offering rebates they just come in and spray spray. no baffles no ventilation i dont get it.
Can you show what you mean? Like what is the right way and wrong way! Would love to see picture or something that helps illustration your point on how the baffles should be setup and installed with or without closed cell spray foam
I was thinking of using closed cell for my home on the top floor . On top of the flat roof there will also be a 2” foam board insulation installed . Should I not use anything insulation from the bottom of the roof ? Or will I be safe to use closed cell ?
There are videos by lawyers, and news outlets on youtube that purport foam is also a super highway for termites. I guess a lot of exterminators void their termite coverage if a homeowner has foam insulation. The tricky thing there though, is termite mitigation will sometimes use foam to kill the termites... I'm not too familiar with that, but was watching some videos where they state for the foam to work in mitigation of termites, you have to spray it on living termites, or something near that description... I would assume the foam the exterminators use has some sort of insecticide in it, but again, what I watched said it doesn't work unless there are termites alive at the moment... It was just a headache of a topic, and overall, I feel comfortable not using foam at all. I mean fires do happen, who wants to be anywhere near several hundred pounds of foam 'up in smoke'; imagine the particulates throughout the neighborhood.
The termites could actually be attracted to moisture being retained in the wood as a result of the foam providing it with a nice waterproof or water resistant container. I have been doing some more research and haven't yet found anything on termites, but have found something suggesting that certain types of foam also create mold problems. Thanks for your comment and definitely another reason someone might not want to use this product.
I've looked in to the termite thing,and that's all it is "a thing " termites don't seek out foam the termite was already infesting the wood around the spray area,a study I found shows that when termites are exposed to excessive heat and toxic elements they try to vacate there current logging and because they found a easy way out through the foam that's where they will go ,in doing so they will loose over 57% of the colony due to poisoning of the nerves system,CAN someone guess WHY!!! Isocyanate attacks the nerves system via the cyanide
I am buying a house that renovated 2018 with foam insulated and new roof. 🤔 my concerns is to unable to identify the leak and/or moisture in the wood. What would you recommend to inspect?
I used to work on closed cell foam extrusion. Closed cell is a vapar barrier. Study thermo bridging and thermo breaks why condensation and roof leaks happens.
So are saying Closed Cell spray foam is ok to use in attic ceilings? I'm in texas and would like to be sure if this is good for condition my attic space as it gets upwards of 150+ degrees during the summers in the attic space and I was told CCSF was a great Solution to this!
OPEN Cell is class 3 vapor retardant so as lumber. So its is a vapor retardant maybe not a complete barrier. You would need significant vapor drive and high relitive humidity to actually saturate open cell from moisture in air. Like pool area or northern alaska in a winter Open cell will let water through with gravigravity. Usually roof leack shows up in about a week. Closed cell doesn't let any water trough.
It soaks up the water, seen some soggy messes and Matt Riser did a demo that didn't go well in my opinion. He flashed a video of a home after a flood and you could squeeze water out, too many mistakes can happen from faulty application too and no way to know if it's faulty.
Yes and closed cell foam wil trap moisture in between the product and the wood. You should NEVER use closed cell foam for wooden floors. And it should be illegaal
Excellent presentation. I do not understand why builders do not coat all the studs, rafters and trusses, and purlins, joist, etc. before installation and add a coat as the go, and and a finish coat, before installing vapor-barriers.
I understand your concern and see why you came to the conclusion but if trapping water between the roof and the insulation is such an issue than why does batt insulation come with a water proof backing? Do you suggest tearing off the water proof backing prior to lining the cavity of the joists? I live in Texas and the vast majority of homes are slab on grade so I cannot speak to the pier and beam homes.
I couldn't find any waterproof backing on fiberglass batt insulation, feel free to put the name of the product in your next comment, just don't put a link to the product or it will be removed. I'm simply suggesting to use fiberglass batt insulation if it will work for your particular project.
My roof is already leaking and its going to cost me $30000 to replace my roof, i dont have the money rn, do u recommend i spray foam my roof as a temporary water repellent till i can afford a new roof?
I agree with andrey, try to find the leaks and make the repairs if you don't have the money to replace the roof. The last thing you want to do is going debt, then not be able to afford to make your monthly payments and lose the house you just put a new roof on.
$30000 good night, how big is your roof. 14 square of shingles and materials would cost less than $2500. Even with a bigger roof say 20 square materials would still only be about $4000 if that. Are you talking about replacing the roof structure too?
I agree with I think people just do what ever they think makes sense to them , I got one of those dumb ideas , can I put tpo directly over a (old tar and gravel flat roof that I scraped spudded good then put a asphalt emulsion and elastomeric coating with polyester fleece) let me know thanks , the coating is 1 year old but I'm scared it will leak
Well, first line of defense would likely be tar paper, right? At least for the roof. I have tar paper under the hard wood floor but it is flat so the water will probably find the seam at some point. So I have been considering open cell which is what brought me here. My ranch-style house with full basement was built in '72. I recently remodeled the kitchen where I found that the R-11 rockwool insulation on the exterior wall had settled and left approx. 1 foot of zero insulation just below, or better yet right at, the ceiling. My thought is to pull the T-111 crap siding off, have access holes drilled in the MDX (top and bottom) every 16 inches so a company could come spray open cell to fill up the cavity completely (R-3.5 per inch x 3.5 inches = R-12.25). Then have 8' x 4' Hardie siding put in its place to cover up the access holes and have a much more durable exterior. If open cell is not a viable or recommended solution, what is? Thanks in advance to all who answer.
I would contact in insulation contractor in your area for more information. They might another idea and if it was me, I would probably remove the siding and install R-13 fiberglass or an equivalent..
I just don't see this being a significant issue since any small amount of water that makes its way to the joists/rafters can still be expelled outward through the vapor-open surface. The scenario you are showing is still vapor-open on one side. So barring any very large gaps (that allow water to pool) or an exterior vapor barrier (that would trap moisture) this system would still be drying-out when the rain or leaks stop. Also, to the point of spray-foaming entirely: Thermal bridging plays a massive roll in energy loss. To put this into perspective: What do you predict the effective R-Value of a wall is where 90% of it is R100 (massive amounts of insulation) and 10% of the wall is R5 (exposed studs)? R90? R80?... nope. Its R55. ouch. Same goes for windows, and hence the importance of reducing window size and/or Low-E triple-glazing.
It sounds like you're trying to validate the spray foam installation process by using the insulation benefits this product provides and that's fine. I also don't see any significant issues from a small amount of water that could be expelled and removed through some form of ventilation from the building, but do have a problem with the small amount of water that wouldn't or a steady supply of water that wouldn't also.
@@JosephClay I'm simply suggesting that one type of foam creates a watertight container for lumber like roof rafters and the other type acts like a giant sponge, soaking up water that could keep the roof rafters wet for a long period of time, eventually leading to wood damage, but I'm pretty sure I mentioned all of this video. Let me know if this doesn't make sense.
I'm already down to closed cell in the floor only, that porous soggy mess of open cell in the ceiling is scary but people are saying it's best in the ceiling. Water needs to run off if it gets inside so it can dry out and hopefully not damage anything but let me actually watch the video...lol
Another great video. Lots to think about. Im currently deciding on whether or not to foam my 100yo house and i wanted foam specifically for air ceiling but now Im wondering if a combination approach would be better. Open cell foam if sprayed thick enough acts as a barrier to water too so even if some leaks through, a lot of water will remain soaked into the wood members. I wonder if a small amount of foam combined with traditional insulation might yield good enough air sealing but still provide you with a method for detecting leaks (visible water marks/damage).
Almost anything that is waterproof or acts as a barrier can trap water and this is the problem I'm referring to in the video. I don't know if this answers your question, so feel free to ask another one if I didn't.
I've never assembled a building using insulated concrete forms or ICF, but I try to look at it like this, if the majority of new home builders aren't using it, then there's probably a good reason why.
I'm sorry but I've been in the industry for way too long ,and all I've heard in this video is( IF, Possibly, could,maybe,) now if a builds envilope is seal according to a minimum building code and done properly ( not good enough!!),none of the issue this video discribes can happen!,spray foam when manufactured correctly will complement and exceed any building envelope seals,Framing on the other hand is the primary cause of poor envilope seal not foam!! Poor joint connection=gap for water !!
I think you summed up the video, but I think you left something out, the possibility of something possibly going wrong and most definitely that's a possibility. I've been in this business for 40 years and people who think products like these are awesome, usually change their mind when they have to pay for the damages.
I just purchased a Victorian built in 1901. It has new roof and windows. instead of foam what would you recommend to insulate the Attic and crawlspace safely?
You might want to check with local contractors, but I would probably use whatever they're selling in your local lumber yards and home improvement centers. I like the fiberglass insulation.
Fiberglass insulation with a moisture barrier such as visquine on the outside of a good solution for the crawl space. There’s simply no competition for a spray foam roof line though. Your attic can heat to 160° in the summer and that affects your home temps and the efficiency of your AC. Climate control your attic with spray foam and watch your energy bill plummet.
@@JosephClay I have a concern : if the shingles are heated up in hot summer and the spray foam prevent the heat from getting inside the attic. Would the heat buildup accelerate the deterioration of the shingles?
@@onexcomputer no. There’s no heat build up because there’s no space for heat to build up in. The opposite effect actually takes place and the shingles only get heated by the sun and not by the heated attic.
Stucco and siding have been around much longer and we don't see massive issues with those products, but we do see some and like the foam insulation, I'm simply pointing one of them out.
@@gregvancom Actually there are massive issues with stucco used with todays building standards holding too much moisture and not be able to dry. Check out Joseph Lstiburek on you tube. The man has incredible building knowledge with the science and actual real life data to support his findings.
I think the issues you bring up in this video are related to other quality issues & not the spray foam. What you’re saying here is build quality issues involving the entry of water can be compensated for using lower quality products & less efficient building techniques.
I think you're right. Furthermore, I think trying to solve this could create other, just a damaging problems. Let's say the building is in a warm humid climate and someone decides to put a waterproof sheet of plastic over the subfloor and open cell foam under. Moisture is likely to condense on the plastic on a hot day with cooler temps in the building. Same problem, different layer. Similar could occur at the roof. There are others in the building performance and inspection fields that share your concerns regarding roof leaks. In my experience, there are roofs that leak, will leak, or have leaked. Every one of them.
Yes, my biggest concern would be any type of water leaks or ways that water could be absorbed into the sponge like products. As far as roofs leaking, I'm with you, it happens.
Your argument has merit. However you’re only taking into consideration 1 type of foam. Half pound or open cell foam. 2lb foam or closed cell is a water/vapour barrier with just 3 inches.
@@gregvancom and also there are other foams but they are not relevant in this conversation as they are never used on residential homes or high rise condos
There's advantage and dis-advantage to spray foam. If applied correctly to the roof deck, the advantage will way out the dis-advantage. The ONLY dis-advantage : "IF "there's a Water leakage, thru the roof deck . But spray foam is not the culprit. You keep on saying IF, IF, and IF. Open cell foam will let water pass thru and you will see the water spot on your sheet rock. But you never talk about the advantage of spray foam. I"m an AC contractor, we got into spray foam because of the advantage of the product. Spray foam is NOT Flamable, because it's have fire retardent in the chemical.... Do your research. Every house we build, we do the AC and spray foam, and the our customer are very happy with the product, and the savings on their electrical bill. I live in florida and my electricity bill in the summer with 2 ac units is below $200 in the summer. By the way, traditional way, blown in cellulose in the attic is the worst idea. Your putting the coldest thing in your house (your duct and AC) in the Hottest part of the house.
Your comment is confusing and I might need to remove it if you can't provide us with additional information or edit your original response. Spray foam might not be flammable, but it's going to burn if it's around flammable materials like lumber that catch on fire. Then you refer to the water leaking like it's not a big deal, when it really could be. As far as saving money on your electricity bill, you would need to let us know how large of a house you live in, what all of the walls and ceilings are insulated with and what temperature you set the thermostat. You might love this product and I realize other contractors and home builders do also, but I've already seen problems with it.
@@gregvancom I believe what he is referring to is having conditioned space in the attic. If you spray foam the underside of the roof you have a thermal break at the roof line creating conditioned attic space. With blown in insulation if you have an AC unit and ducting running in the attic above the cellulose when the attic gets hot it makes the equipment work much harder and heats up the cool air moving through the ducting. To have an AC unit in an unconditioned attic space makes no sense at all and will increase your hydro bills. Also you keep mentioning spray foam getting wet if the roof leaks. If the roof leaks it doesn't matter what type of insulation you have it will get wet. Soaking wet batt insulation is not fun to remove. Water cannot penetrate closed cell foam.Only open cell foam. Make sure the comparisons are clear. In most cases closed cell out performs open cell and is the preferred choice.
These are all what if’s and left field worst case scenarios. Like if you’re getting water through your roof, then it’s the roofers fault not the foam lol
Dampened plywood is like sponge. Keeps separating layers wider like pot holes on the street as it weakens glue. Other nightmare I worry is re-workabliilty of the house as everything is fully covered; can't find any wiring or plumbing. No house is perfect; it needs expansion as people live. Maybe someone will invent a wall x-ray machine, or insulation melting machine like a heat gun on the snow . No wonder house price is skyrocketing.
So, you have to know the right product for the right job. Open cell foam will allow moisture through, closed cell foam won’t. Learn the new stuff be better.
I asked someone else this question and was wondering if you could elaborate. What exactly would you use either one for. I still believe either one could accelerate the process of wood rotting, especially if it's trapped and no one can see the problem, because it's covered by foam.
@@gregvancom Yes, any prolonged moisture would cause rot. I use closed cell for everything, but most applications are attics. The top of the roof decking always gets a moisture proof vinyl barrier. I use a rafter panel inside and then spray the foam right over it. Keeps the attic cooler because I have the air flow to let the heat (and moisture) out at the ridge vent. Amazon - Insulation Baffle for 24" Rafter Bays by SmartBaffle I totally seal the attic like it is a living space, but you have to use a 85-95% efficient furnace if it is located in the attic. You could use treated lumber, but that may be hard if it is an existing roof. Either way, it will still be out of sight. Maybe you could inspect it from the soffit end with a scope. Good Luck!
Thanks Greg and everyone else throwing in their 2 cents. Seems to me encapsulating the entire floor joist or roof rafters is a very bad idea for the reasons you point out. In between MIGHT be ok but that now seems risky to trap moisture. I do however think what they call flash ( 1” closed cell foam between wall studs) and bat (rockwool) the rest of the cavity is a good idea because moisture won’t get trapped being vertical however as someone else mentioned I can already tell from all the comments this will limit potential buyers (never a good thing) and if word gets out and spreads to stay away from spray foam at all costs (say in 10 years) from horror stories it will get much worse and you’ll have to sell at a BIG discount or have it removed (what a nightmare that would be). I was planning on using it but I now think it’s way too risky. Thanks again this video may have saved me 10’s of thousands down the road and even if not I’m sure I’ll sleep better not taking the chance.
You're welcome and I'm glad you understand that I'm only pointing out my observations. People really need to do research like you're doing and gather other people's opinions about construction products that haven't been thoroughly tested for decades.
Just re-did my roof. House was built in 1965 with less than a 2/12 roof pitch. Major ice damming for years. Pulled the old roof/plywood off and spray foamed to R-36 from the top onto the ceiling drywall leaving a 2" air space at top of rafters with plywood at ridge cut back 6" for ridge vent. Sheathed with plywood. Covered plywood with ice and water shield leaving ridge cavity open. Strapped plywood 1 1/2" air space with 1x4. Used standing seam metal roofing. I have venting within the cavity and a vented over roof. Custom soffit intake vent with a continuous Maximum ridge vent made from steel that resembles a tunnel on the ridge with two Maximum roof ventilators. Not only does the cavity itself vent but the underside of the steel has a constant air wash removing any condensation that may form from temperature fluctuations. We live in southern Ontario Canada. Not only have our heating and cooling bills been reduced but we no longer have any ice damming in @t yes spray foam does work and in this application it performs quite well. Ventilation is key. You can have an R-80 roof but if you do not have proper ventilation you will get ice damming and possibly condensation/moisture issues. Do the research and engineered properly spray from out performs batt insulation hands down. Just ask Mike Holmes what he thinks of spray foam.
Thanks for the feedback, how do you setup ventilation correctly to get the results you mentioned?
I'm doing work on a 100 year old house. We gutted the inside and there is no dry rot or any kind of bug damage anywhere. It has wood shingles, tar paper and diagonal 1x6" wood sheathing. I think this says something for a structure where water can evaporate. Thanks for the video and your thoughts on the subject.
It says something for a structure where water can evaporate via massive amounts of air infiltration and massive amounts of fuel usage to heat the structure and keep the air dry. Moisture tends to cause damage to a house when you have the temerity to insulate things in order to reduce heat loss. An older house in winter is an enormous dehydrator, pulling in air with low absolute moisture and heating it up. The downsides are large amounts of fuel usage, and ice damming. If the roof is steep and well-sealed enough to avoid the ice dams, things can work fairly well.
Air conditioning can also cause significant issues in warm climates.
@@TrogdorBurnin8or , I hear what you're saying, makes a lot of sense. I guess here in northern California, where the weather is mild, the heating losses are not as important as other parts of the country.
Good point by trogdor. The weather does make a big difference and I think this is why this foam product sounds so appealing. However, foam might be an excellent product for reducing airflow and lowering heating costs, but at what cost, especially if it leads to expensive home repairs in the future. By the way, there are thousands of homes like yours that are still doing just fine.
@@tomruth9487 I'm in south Texas and do it to keep heat out of attics. I use a rafter panel inside and then spray the foam right over it. Keeps the attic cooler because I have the air flow to let the heat (and moisture) out at the ridge vent. Amazon - Insulation Baffle for 24" Rafter Bays by SmartBaffle
@@TK-qm8rb thanks for the tip and product recommendation
Appreciate this video, Greg. I'm slow renovating a 115-year old two-flat house here in Chicago. It's evident the old owners, and owners before them, deferred maintenance and upkeep. The attic has zero insulation, its also the default mechanical room with the water heaters up there (one was made in 1994!) I've brought in insulation companies and they've all suggested open-cell spray foam. Which I'm not a fan of because ventilation/evaporation and fire melt point. I'm looking into mineral wool batts and all the companies I've had out are saying that's not a smart idea because of cost. Your video has confirmed my decision to go with mineral wool and Reflectix panels in the attic and crawl space (which is a whole different mess).
Funny how the algorithm works.
Thanks.
Better to use the old methods when you're not 100 percent sure about the new stuff.
I've had the same thought s on this! I've decided on a metal roof and puting the 1in. Gap between the roof sheeting and foam yousing foil foam for the raident barrier. So i get much-needed air flow with any moisture being able to vent outside ! Now the floor has its owen challenges ! So i decided to youse till with water repellant grouting with a drain by the toilet area and bathtub area. Is it full proof well im hoping 90% and it will be someone else's problem when the 10% kicks in.
I did some looking into this a few years back when I was encapsulating my crawlspace. I found some research that suggested that moisture will transfer through the wood floor and floor joists and deposit and trap at the point between the wood and foam (warm moist air from above will form water when in contact with the cool crawl space). It also suggested that attaching a membrane / vapour barrier in the crawl space to the under side of the joists is bad.
I agree with practically everything you said and since waterproof vapor barriers can trap moisture, then it would make sense to avoid using them, especially on buildings made of wood.
@@gregvancom Would a Conditioned Crawl space and Attic with Vapor barrier in a crawlspace good thick water resistant underlayment on top of the roof sheathing fix all the water and moisture problems? Wouldn’t the instal a dehumidifier in both attic and condition basement help further? I understand the need to detect leaks from loose roof shingles, but isn't that up to the owner to be diligent by inspecting his own roof from time to time? Especially after a downpour? I guess the increased in R Value with CLOSED or OPEN spray foam as apposed to other types of insulation sacrifices leak detection.
I’ve been on several roofs with completely rotted plywood with absolutely no sign of leaking on the drywall of the interior of the house with both closed and open cell insulation. We will see huge problems in the near future with homes sprayed with foam and the roof dried in with peal-n-stick/ ice and water shield. Plywood has to breath if not it will dry rot and that’s what we will see a lot of in the next 10-15 years
Wow, talk about the double wammy and I agree. I think this could be the next big problem in the industry and thanks for sharing.
Would u rather have to replace just the roof deck or redo a ton of drywall? I opt for the former.
What you are getting at is a totally valid point. Craftsmanship is almost never perfect. I think that this could really cause problems especially in the roof structure where water is most likely to penetrate. Being that closed cell foam wont let water leak through the structure, you would not notice a leak. Even with elevation creating some drainage the wood will still absorb some of that water. Very valid point, glad i watched this video. It will make me think that much deeper into the use of spray foam.
Glad I could help and thanks for putting it a different way. I hope others read your comment and also find value in the video.
-- Foam allows water to seep/creep past it.
This is an issue solved at the water/vapor control layer for the roof decking.
If you're that worried, waterproof and edge/gap seal the primary roof deck.
Set firring and lay down a secondary deck (which you also waterproof) if you're laying shingles/tile.
For metal roofing, simply lay the roof on.
-- Foam allows water retention in flooring.
Planning issue.
If you're inside a conditioned space, unless you're dealing with insane amounts of prolonged water exposure (the house is flooded out), most reasonable water exposure is set to dry to the interior.
Sure, you might have to pop up decorative flooring if it's bad enough. But there are a few tile/wood flooring systems that allow you to pop up individual tiles/boards (or the whole floor if necessary) and let the floor dry out properly.
And if are worried about the subfloor gapping, double-subfloor or tape the gaps.
You do bring up a couple of points.
@@gregvancomnot to sound lime a idiot but can you illustrate this on how this would work via video simulation? I'm interested and close to getting my attic spray foamed but want to truly get good honest
Feedback before doing this!
I’ve been thinking the same thing.... well not EXACTLY the same. But close! Everyone has been telling me to do it but there hasn’t been enough time for it to give answers.
I totally agree and have a difficult time understanding why people are susceptible to anything that sounds like it will work, even when it doesn't or in this case can produce unnecessary home repairs in the future.
Good to question spray foam greg. The marketing for the stuff is huge and I've been attacked by shills for making comments doubting spray
If it doesn't make sense, don't use it and if it's new, then don't use it until it's been thoroughly tested.
This confirms that there is no winning the insulation battle with any kind of product.
Aside from water issues, spray foam is EXTREMELY flammable. This was the deciding factor for me coupled with the cost of closed cell.
I will definitely have to do a little more research on that one and thanks for sharing.
Oh wow. totally not true.
Exactly right. Very flammable. Major issue. Also very toxic smoke during burn.
Its a class 1 fire retardant...ie if a piece of wood is burning it will burn. take the wood away it will extinguish itself....if it was so dangerous it wouldn't be used in fire walls and it is used in conjunction with fire retardant paint
Wrong, there is video proof that spray foam does not burn itself as there is nothing flammable about it.
Maybe when the spray foam is being applied and curing then it would be flammable, but not once it has cured.
The issue of leak detection is a legitimate concern. Hopefully there is a foam product with a visual indicator, perhaps the foam could change color if it gets wet.
I like it and great tip.
What are your thoughts on placing a baffle in between the trusses and the spraying the foam insulation. That way if there is a leak, the baffle will collect the water and the water will slide down and out. Thanks.
Bad idea. Much of the effectiveness of the Foam lies in its adherence to the substrate and preventing heat build up
@@JosephClay How does adherence to the substrate prevent heat build up as opposed to placing a baffle between the substrate and spray foam? If you spray a layer of foam on the interior of the house you create a thermal break regardless if there is space between the foam and substrate. If anything the baffle would create airflow and if there ever was a roof leak it would allow the substrate to dry. In a climate with extreme fluctuating temperatures a vented over roof is recommend over even a spray foamed roof (hot roof). Joseph Lstiburek has the data to back this up.
@@jeffleicher3579 the only reason for airflow is the heat builds up enough. Turbines work properly when the heat builds up and causes airflow. Airflow is caused by heat build up. Not by air space
@@JosephClay I should have explained further. In addition to the baffle you would have an air intake at the bottom at the overhang and a ridge vent on top creating airflow between the baffle and substrate. In cold climates you have heat loss regardless of R-value which in turn could result in ice damming without ventilation in the roof whether it be a vented over roof or a vented attic space. In warm climates it dissipates heat.
Turbines are often not good solution for airflow as they can create negative pressure in the attic space which in turn can suck cold or warm air from the the interior of the building envelope if it is not air sealed properly. (In a traditional attic space) Meaning higher heating or cooling costs and unbalanced ventilation.
In addition should the roof ever fail and leak the air space would allow the substrate to dry. If you have spray foam on the underside of the substrate and then an ice and water shield you have essentially created a vapour lock within the roof system ....in a cathedral application... in which the rafters would become saturated with water and perhaps never dry because there is no ventilation.
@@jeffleicher3579I would love to hear more on how this works, love to see some kind of example or illustrate that shows how all this would work. I'm in process of getting ym attic CCSF installed on attic ceilings and want to be sure it's good all around idea!
Great great video just wish these individuals who comment would share some diagrams or pictures and or illustrations to better understand the argument. Not to say the argument is not valid as many of us are learning through this channel and hope these commentd with ideas suggestions or compelling arguments would have some demo's, illustrations similar to how your videos are setup with visual simulations super easy to understand and learn from!
If leack is minor moisture will be taken care with AC/ dehumidifier. Fiberglass on other hand will be completely ruined and ready for "creating new life".. mold.
So no.. foam is not an issue
Let me see if I can make sense out of your statement, a minor leak with small amounts of moisture, might not be a problem, but bigger leaks could be, but it's okay to use foam, but what type of foam? Lotta loose ends in your comment. Feel free to remove it if you want to or provide us with more details.
I think what we're all trying to achieve is huge r-values but allowing all materials that can rot to breathe. . . I'm not sure anyone has got there with the spray foams. The open cell can pass water but the drying cycle is longer than the dry season in a lot of climates. Sure 150 year old homes show no sign of rot with very very low r-values which means energy bills that outweigh the cost of rebuilding every 50 years. It's a balancing act with our technology it seems. . . Live in a Ziploc bag and rot or live in a paper bag and swelter/freeze. Gotta be a middle.
Good points and I think what I'm trying to explain in this video is the fact that there are plenty of builders who for whatever reason have a difficult time figuring out the pros and cons of new products.
Exactly as long as spray foam been used, there should be a know fact. Like putting diesel in a gas engine or gasoline in the engine oil is bad and car deadly . But with foam it like I'll sell it to you but I don't have it in my home, or if I did use foam I'm gonna sell it and move let someone else buy the problem
You are supposed to add baffles and then the insulation. The baffles connect to the eaves and the vents in the eaves travel through the baffles to the ridge vent
That will help.
none of the foam guys are bothering to do this. energy companies are offering rebates they just come in and spray spray. no baffles no ventilation i dont get it.
Can you show what you mean? Like what is the right way and wrong way! Would love to see picture or something that helps illustration your point on how the baffles should be setup and installed with or without closed cell spray foam
I was thinking of using closed cell for my home on the top floor . On top of the flat roof there will also be a 2” foam board insulation installed . Should I not use anything insulation from the bottom of the roof ? Or will I be safe to use closed cell ?
I would consider using fiberglass insulation if possible.
Check with local building authorites or building department if you have one for more information on common construction practices in your area.
There are videos by lawyers, and news outlets on youtube that purport foam is also a super highway for termites. I guess a lot of exterminators void their termite coverage if a homeowner has foam insulation. The tricky thing there though, is termite mitigation will sometimes use foam to kill the termites... I'm not too familiar with that, but was watching some videos where they state for the foam to work in mitigation of termites, you have to spray it on living termites, or something near that description... I would assume the foam the exterminators use has some sort of insecticide in it, but again, what I watched said it doesn't work unless there are termites alive at the moment... It was just a headache of a topic, and overall, I feel comfortable not using foam at all. I mean fires do happen, who wants to be anywhere near several hundred pounds of foam 'up in smoke'; imagine the particulates throughout the neighborhood.
The termites could actually be attracted to moisture being retained in the wood as a result of the foam providing it with a nice waterproof or water resistant container. I have been doing some more research and haven't yet found anything on termites, but have found something suggesting that certain types of foam also create mold problems. Thanks for your comment and definitely another reason someone might not want to use this product.
I've looked in to the termite thing,and that's all it is "a thing " termites don't seek out foam the termite was already infesting the wood around the spray area,a study I found shows that when termites are exposed to excessive heat and toxic elements they try to vacate there current logging and because they found a easy way out through the foam that's where they will go ,in doing so they will loose over 57% of the colony due to poisoning of the nerves system,CAN someone guess WHY!!! Isocyanate attacks the nerves system via the cyanide
I am buying a house that renovated 2018 with foam insulated and new roof. 🤔 my concerns is to unable to identify the leak and/or moisture in the wood.
What would you recommend to inspect?
I am buying as is, no home inspection. That's worries me. Is it bad to live with foam insulation?
I used to work on closed cell foam extrusion. Closed cell is a vapar barrier. Study thermo bridging and thermo breaks why condensation and roof leaks happens.
So are saying Closed Cell spray foam is ok to use in attic ceilings? I'm in texas and would like to be sure if this is good for condition my attic space as it gets upwards of 150+ degrees during the summers in the attic space and I was told CCSF was a great
Solution to this!
Open cell foam will allow moisture through, closed cell foam won’t.
That's what I found in my research also.
OPEN Cell is class 3 vapor retardant so as lumber. So its is a vapor retardant maybe not a complete barrier. You would need significant vapor drive and high relitive humidity to actually saturate open cell from moisture in air. Like pool area or northern alaska in a winter
Open cell will let water through with gravigravity. Usually roof leack shows up in about a week. Closed cell doesn't let any water trough.
It soaks up the water, seen some soggy messes and Matt Riser did a demo that didn't go well in my opinion. He flashed a video of a home after a flood and you could squeeze water out, too many mistakes can happen from faulty application too and no way to know if it's faulty.
Yes and closed cell foam wil trap moisture in between the product and the wood. You should NEVER use closed cell foam for wooden floors. And it should be illegaal
Amazing videos.
Excellent presentation. I do not understand why builders do not coat all the studs, rafters and trusses, and purlins, joist, etc. before installation and add a coat as the go, and and a finish coat, before installing vapor-barriers.
What would the coat them with?
I understand your concern and see why you came to the conclusion but if trapping water between the roof and the insulation is such an issue than why does batt insulation come with a water proof backing? Do you suggest tearing off the water proof backing prior to lining the cavity of the joists? I live in Texas and the vast majority of homes are slab on grade so I cannot speak to the pier and beam homes.
I couldn't find any waterproof backing on fiberglass batt insulation, feel free to put the name of the product in your next comment, just don't put a link to the product or it will be removed. I'm simply suggesting to use fiberglass batt insulation if it will work for your particular project.
My roof is already leaking and its going to cost me $30000 to replace my roof, i dont have the money rn, do u recommend i spray foam my roof as a temporary water repellent till i can afford a new roof?
foam is not waterproof . Try to find leaks with an infrared camera and make patches
I agree with andrey, try to find the leaks and make the repairs if you don't have the money to replace the roof. The last thing you want to do is going debt, then not be able to afford to make your monthly payments and lose the house you just put a new roof on.
PUA Guy Very bad idea.
$30000 good night, how big is your roof. 14 square of shingles and materials would cost less than $2500. Even with a bigger roof say 20 square materials would still only be about $4000 if that. Are you talking about replacing the roof structure too?
No. Fix your roof first. Foam is not a substitute for a functioning roof
I agree with I think people just do what ever they think makes sense to them , I got one of those dumb ideas , can I put tpo directly over a (old tar and gravel flat roof that I scraped spudded good then put a asphalt emulsion and elastomeric coating with polyester fleece) let me know thanks , the coating is 1 year old but I'm scared it will leak
I would check with the product manufacturers for more information.
@@gregvancom ill just do what i thinks then i already done over 16 hours of research i was just trying to see what common sense told me to do
Well, first line of defense would likely be tar paper, right? At least for the roof. I have tar paper under the hard wood floor but it is flat so the water will probably find the seam at some point. So I have been considering open cell which is what brought me here. My ranch-style house with full basement was built in '72. I recently remodeled the kitchen where I found that the R-11 rockwool insulation on the exterior wall had settled and left approx. 1 foot of zero insulation just below, or better yet right at, the ceiling. My thought is to pull the T-111 crap siding off, have access holes drilled in the MDX (top and bottom) every 16 inches so a company could come spray open cell to fill up the cavity completely (R-3.5 per inch x 3.5 inches = R-12.25). Then have 8' x 4' Hardie siding put in its place to cover up the access holes and have a much more durable exterior. If open cell is not a viable or recommended solution, what is? Thanks in advance to all who answer.
I would contact in insulation contractor in your area for more information. They might another idea and if it was me, I would probably remove the siding and install R-13 fiberglass or an equivalent..
@@gregvancom Fiberglass?!?!?!? Tom would be going backwards removing roxul installation for fiberglass.... woah!
I just don't see this being a significant issue since any small amount of water that makes its way to the joists/rafters can still be expelled outward through the vapor-open surface. The scenario you are showing is still vapor-open on one side. So barring any very large gaps (that allow water to pool) or an exterior vapor barrier (that would trap moisture) this system would still be drying-out when the rain or leaks stop.
Also, to the point of spray-foaming entirely: Thermal bridging plays a massive roll in energy loss.
To put this into perspective: What do you predict the effective R-Value of a wall is where 90% of it is R100 (massive amounts of insulation) and 10% of the wall is R5 (exposed studs)?
R90? R80?... nope. Its R55.
ouch. Same goes for windows, and hence the importance of reducing window size and/or Low-E triple-glazing.
It sounds like you're trying to validate the spray foam installation process by using the insulation benefits this product provides and that's fine. I also don't see any significant issues from a small amount of water that could be expelled and removed through some form of ventilation from the building, but do have a problem with the small amount of water that wouldn't or a steady supply of water that wouldn't also.
2:52 that’s why we spray open cell on rooflines except for special applications.
So instead of a watertight floor joist container, you like the giant sponge surrounding the joist.
gregvancom I mentioned roofline not floor. I don’t think I understand your question.
@@JosephClay I'm simply suggesting that one type of foam creates a watertight container for lumber like roof rafters and the other type acts like a giant sponge, soaking up water that could keep the roof rafters wet for a long period of time, eventually leading to wood damage, but I'm pretty sure I mentioned all of this video. Let me know if this doesn't make sense.
I'm already down to closed cell in the floor only, that porous soggy mess of open cell in the ceiling is scary but people are saying it's best in the ceiling. Water needs to run off if it gets inside so it can dry out and hopefully not damage anything but let me actually watch the video...lol
You definitely need an open cell product when insulating wood to prevent rot and mold.
Another great video. Lots to think about. Im currently deciding on whether or not to foam my 100yo house and i wanted foam specifically for air ceiling but now Im wondering if a combination approach would be better. Open cell foam if sprayed thick enough acts as a barrier to water too so even if some leaks through, a lot of water will remain soaked into the wood members. I wonder if a small amount of foam combined with traditional insulation might yield good enough air sealing but still provide you with a method for detecting leaks (visible water marks/damage).
Almost anything that is waterproof or acts as a barrier can trap water and this is the problem I'm referring to in the video. I don't know if this answers your question, so feel free to ask another one if I didn't.
If water gets in, it needs a way to get out.
Haven't heard from you in a while and I agree with you 100%.
That's what I said, open cell also soaks it up and will hold it so imagine the foam keeping the water wet, if you can say "keep water wet"...lol
What’s your opinion on ICF building?
I've never assembled a building using insulated concrete forms or ICF, but I try to look at it like this, if the majority of new home builders aren't using it, then there's probably a good reason why.
gregvancom I would assume cost right?
That's why it's critical to get waterproofing right on outside of ICF building.
I'm sorry but I've been in the industry for way too long ,and all I've heard in this video is( IF, Possibly, could,maybe,) now if a builds envilope is seal according to a minimum building code and done properly ( not good enough!!),none of the issue this video discribes can happen!,spray foam when manufactured correctly will complement and exceed any building envelope seals,Framing on the other hand is the primary cause of poor envilope seal not foam!! Poor joint connection=gap for water !!
I think you summed up the video, but I think you left something out, the possibility of something possibly going wrong and most definitely that's a possibility. I've been in this business for 40 years and people who think products like these are awesome, usually change their mind when they have to pay for the damages.
Hahahha yah exactly
Thanks for the like
So dont get a Cat or Dog ???
I just purchased a Victorian built in 1901. It has new roof and windows. instead of foam what would you recommend to insulate the Attic and crawlspace safely?
You might want to check with local contractors, but I would probably use whatever they're selling in your local lumber yards and home improvement centers. I like the fiberglass insulation.
Fiberglass insulation with a moisture barrier such as visquine on the outside of a good solution for the crawl space. There’s simply no competition for a spray foam roof line though. Your attic can heat to 160° in the summer and that affects your home temps and the efficiency of your AC. Climate control your attic with spray foam and watch your energy bill plummet.
@@JosephClay I have a concern : if the shingles are heated up in hot summer and the spray foam prevent the heat from getting inside the attic. Would the heat buildup accelerate the deterioration of the shingles?
@@onexcomputer no. There’s no heat build up because there’s no space for heat to build up in. The opposite effect actually takes place and the shingles only get heated by the sun and not by the heated attic.
Spray foam has been around for 40 years... We would see mass issues if it was a problem, but we don't.
Stucco and siding have been around much longer and we don't see massive issues with those products, but we do see some and like the foam insulation, I'm simply pointing one of them out.
@@gregvancom Actually there are massive issues with stucco used with todays building standards holding too much moisture and not be able to dry. Check out Joseph Lstiburek on you tube. The man has incredible building knowledge with the science and actual real life data to support his findings.
jeff leicher Most issues aren’t synthetic stucco and bad installers
I think the issues you bring up in this video are related to other quality issues & not the spray foam. What you’re saying here is build quality issues involving the entry of water can be compensated for using lower quality products & less efficient building techniques.
No, if the foam traps water because a higher quality product fails or more efficient building techniques fail, then you have a problem.
4:30 1/8 of an inch between tongue and groove subfloor?
I think you're right. Furthermore, I think trying to solve this could create other, just a damaging problems. Let's say the building is in a warm humid climate and someone decides to put a waterproof sheet of plastic over the subfloor and open cell foam under. Moisture is likely to condense on the plastic on a hot day with cooler temps in the building. Same problem, different layer. Similar could occur at the roof. There are others in the building performance and inspection fields that share your concerns regarding roof leaks. In my experience, there are roofs that leak, will leak, or have leaked. Every one of them.
Yes, my biggest concern would be any type of water leaks or ways that water could be absorbed into the sponge like products. As far as roofs leaking, I'm with you, it happens.
Your argument has merit. However you’re only taking into consideration 1 type of foam. Half pound or open cell foam. 2lb foam or closed cell is a water/vapour barrier with just 3 inches.
I believe I mentioned two types of foam, but if there is another, let me know and I will look into it.
@@gregvancom if that’s so then you’re not taking into consideration what closed cell foam actually offers in comparison to open cell foam
@@gregvancom and also there are other foams but they are not relevant in this conversation as they are never used on residential homes or high rise condos
There's advantage and dis-advantage to spray foam. If applied correctly to the roof deck, the advantage will way out the dis-advantage. The ONLY dis-advantage : "IF "there's a Water leakage, thru the roof deck . But spray foam is not the culprit. You keep on saying IF, IF, and IF. Open cell foam will let water pass thru and you will see the water spot on your sheet rock. But you never talk about the advantage of spray foam. I"m an AC contractor, we got into spray foam because of the advantage of the product. Spray foam is NOT Flamable, because it's have fire retardent in the chemical.... Do your research. Every house we build, we do the AC and spray foam, and the our customer are very happy with the product, and the savings on their electrical bill. I live in florida and my electricity bill in the summer with 2 ac units is below $200 in the summer. By the way, traditional way, blown in cellulose in the attic is the worst idea. Your putting the coldest thing in your house (your duct and AC) in the Hottest part of the house.
Your comment is confusing and I might need to remove it if you can't provide us with additional information or edit your original response. Spray foam might not be flammable, but it's going to burn if it's around flammable materials like lumber that catch on fire. Then you refer to the water leaking like it's not a big deal, when it really could be. As far as saving money on your electricity bill, you would need to let us know how large of a house you live in, what all of the walls and ceilings are insulated with and what temperature you set the thermostat.
You might love this product and I realize other contractors and home builders do also, but I've already seen problems with it.
Very well understood! The AC is trying to work in an oven.
@@gregvancom I believe what he is referring to is having conditioned space in the attic. If you spray foam the underside of the roof you have a thermal break at the roof line creating conditioned attic space. With blown in insulation if you have an AC unit and ducting running in the attic above the cellulose when the attic gets hot it makes the equipment work much harder and heats up the cool air moving through the ducting. To have an AC unit in an unconditioned attic space makes no sense at all and will increase your hydro bills.
Also you keep mentioning spray foam getting wet if the roof leaks. If the roof leaks it doesn't matter what type of insulation you have it will get wet. Soaking wet batt insulation is not fun to remove.
Water cannot penetrate closed cell foam.Only open cell foam. Make sure the comparisons are clear. In most cases closed cell out performs open cell and is the preferred choice.
Your last sentence makes sense. I imagine having am the ac unit outside is not the same. Thanks
For your roof scenario, you are implying the roof has failed correct?
Yes, if roofing fails, you could have a problem.
These are all what if’s and left field worst case scenarios. Like if you’re getting water through your roof, then it’s the roofers fault not the foam lol
The right way to do it is do the gaps between the joists not the hole joists. With this the wood on tye bottom would me exposed and not sealed.
That seems like it might work better.
Nothing is perfect. Everything that's done to tighten up a house needs to br addressed with an i upgraded system to get rid of moisture.
As long a you're expecting the possibility of problems then at least you won't be blindsided when or if they come.
Dampened plywood is like sponge. Keeps separating layers wider like pot holes on the street as it weakens glue. Other nightmare I worry is re-workabliilty of the house as everything is fully covered; can't find any wiring or plumbing. No house is perfect; it needs expansion as people live. Maybe someone will invent a wall x-ray machine, or insulation melting machine like a heat gun on the snow . No wonder house price is skyrocketing.
Spray Foam is easy to cut out at the point of rework and easy to replace. Often a can from Lowe’s does the trick or a Froth Pack for a bigger patch.
Your right! That your wrong sorry.
Interesting reply, but how about putting a little effort into elaborating or providing a reason why I could be right or wrong.
So, you have to know the right product for the right job. Open cell foam will allow moisture through, closed cell foam won’t. Learn the new stuff be better.
I asked someone else this question and was wondering if you could elaborate. What exactly would you use either one for. I still believe either one could accelerate the process of wood rotting, especially if it's trapped and no one can see the problem, because it's covered by foam.
@@gregvancom Yes, any prolonged moisture would cause rot. I use closed cell for everything, but most applications are attics. The top of the roof decking always gets a moisture proof vinyl barrier. I use a rafter panel inside and then spray the foam right over it. Keeps the attic cooler because I have the air flow to let the heat (and moisture) out at the ridge vent. Amazon - Insulation Baffle for 24" Rafter Bays by SmartBaffle
I totally seal the attic like it is a living space, but you have to use a 85-95% efficient furnace if it is located in the attic.
You could use treated lumber, but that may be hard if it is an existing roof. Either way, it will still be out of sight. Maybe you could inspect it from the soffit end with a scope. Good Luck!
Thanks Greg and everyone else throwing in their 2 cents. Seems to me encapsulating the entire floor joist or roof rafters is a very bad idea for the reasons you point out. In between MIGHT be ok but that now seems risky to trap moisture. I do however think what they call flash ( 1” closed cell foam between wall studs) and bat (rockwool) the rest of the cavity is a good idea because moisture won’t get trapped being vertical however as someone else mentioned I can already tell from all the comments this will limit potential buyers (never a good thing) and if word gets out and spreads to stay away from spray foam at all costs (say in 10 years) from horror stories it will get much worse and you’ll have to sell at a BIG discount or have it removed (what a nightmare that would be). I was planning on using it but I now think it’s way too risky. Thanks again this video may have saved me 10’s of thousands down the road and even if not I’m sure I’ll sleep better not taking the chance.
You're welcome and I'm glad you understand that I'm only pointing out my observations. People really need to do research like you're doing and gather other people's opinions about construction products that haven't been thoroughly tested for decades.
So not true
Hard to argue with.