Conditioned Attics vs. Vented Attics: Matt Risinger and Hunter Panels
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- Опубліковано 31 лип 2024
- What's the difference between a conditioned and a vented attic, and how does Matt Risinger build conditioned assemblies for his projects?
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Having an attic contained within the conditioned envelope of a building requires some savvy construction practices in order to maintain the integrity of the structure and reduce the chance of extreme condensation. Today on The Metal Roofing Channel, Matt Risinger of The Build Show joins Thad to discuss the differences between a conditioned attic and a vented attic, why Matt has built conditioned attics for many years, and a variety of assembly options to choose from. They also look at Matt's current project in Austin, Texas, and explore how he used a product called Hunter Panels to achieve proper eave to ridge ventilation even with a conditioned attic.
Topics covered:
►Intro 00:00
►Conditioned vs. vented attics 0:46
►Matt's project and Hunter Panels 2:45
►Polyiso insulation installation 5:47
Check out Matt Risinger's UA-cam channel to watch content on all kinds of building techniques!
Please note the installation details and methods shown in this video are for reference only. Sheffield Metals recommends following their published installation details or for WTW projects following the required details issued and marked approved for that specific project.
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I hate the closing on Matt's channel but for some reason I loved his silent "on the build show" here 🤣
I'm seriously so grateful for all of the knowledge that both of you continue to share. Also, your appreciation for best practices is infectious! Thank you both!
Thank you for watching and supporting the channel! -Thad
Conversations like these make me realize how little I know.
One could really nerd out and learn a lot about roofing and home building from you guys. Great stuff, gentlemen.
You guys are such a huge help. I can't wait for my Sheffield roof here in Boise, Idaho!
Two of my favorite channels
Thanks for the support! -Thad
Thanks for the video guys
Follow both of you. Great to see you in the same frame.
Always a great time getting to do some work with Matt! Thanks for watching! -Thad
Great content. The close was funny seeing Matt try to close on someone else video. Y'all should have coordinated the close! LOL glad y'all put it in still. Love it
This was crazy good.
Yes nailed it! Vented roof but sealed from the inside. Thats perfect.
Please post the assembly details somewhere
Thanks for sharing this. I'm intending to convert my attic space from vented to conditioned, but so much of the information poo-poos non-vented attics. I'm gonna cook the shingles; I'm gonna grow mold and rot the two-by's! And so on.The only reason I'd do this is because I have ducting in the attic. (Well, I DO have ducting in the attic, and the furnace and A/C cooling coils! )
Anyway, I'm in Southern California and we have yearly wind events, the Santa Ana winds, and usually the associated wildfires, and not enough feral cats to control the rats. So more often than not nasty rodents find a way in through the vents (they're smart enough to chew through the screening!).
So once again, thanks for encouraging me to go the conditioned attic route.
So much is location on planet earth and budget. Thank you for the video, January 2024 🎈
What about the OSB underneath the cool-vent panel? It's got polyiso directly on top, and closed cell spray foam underneath. Doesn't that make it sandwiched between two vapor barriers? How will it dry?
So how is the air sealing of the roof deck done with the Hunter panels? Just the spray foam inside? Also, won't the polyiso of the Hunter panels shrink some over time and pull away from each other?
Thanks!
Thank you for watching! -Thad
what if my house has metal roof right on shingles thinking about sprayfoaming with closed cell
Matt, I'm honestly delighted, no THRILLED to see you tackle the best engineering solutions for attic ventilation and cooling. Forgive me if you've already answered this question elsewhere: do you think a reflective foil would help to minimize downward heat radiation in the air gap inside those Hunter panels? A foil facing UP would help to "bounce" radiant heat back into that air gap, further warming the air that is passively moving (and rising) up that air gap. You can call it the RISING-AIR SOLUTION (patent pending) :) Hope you MAKE A MILLION with that new product concept! KEEP UP THE GOOD WORK, as always.
After browsing several of the comments here, I can think of a low budget approach that is similar to Hunter panels. This idea could work great with a small house and relatively small roof area: start with 1/2" plywood sheathing fastened to rafters normally. Then, "sister" 2x2" runners centered exactly over all rafters. Then, attach a final layer of 5/8" sheathing to those runners. Any good carpenters can work up the soffit and ridge details. Depending on budget, reflective foil can be placed on the first layer of 1/2" plywood. The basic concept is to create a passive RISING-AIR gap, with intake at soffits and exhaust at ridge vent (pun intended :) And, thinking further, this low-budget concept might also work when new shingles are being installed to replace old shingles, especially if existing sheathing does not need to be replaced.
They sell foil faced sheathing. No need to make it.
Sharkskin on top of Foxx? its just at the ridge right, for breathability?
Depends on the climate where you live. A conditioned attic makes more sense in warmer climates where the HVAC systems are located. Here in zone 6, HVAC is located in basements for the most part. Many homes in the south don't have basements since frost lines are shallow and not worth the cost for the 9'+ excavation. I'm building a home in MN and will have a vented attic. Top of ceiling drywall will be spray foamed with closed cell to 2" with blown-in on top to R-50. Having roof trusses would limit the space for a usable attic, so no sense to condition the attic space by spray foaming the underside of the roof deck.
Our current home uses stick joists with vaulted ceilings, so no attic and the insulation between the roof joists is closed cell foam.
Your current home is essentially what they are talking about minus the ceiling joists and location of the finish.
Hi Matt came across your shows and I’m really enjoying your content. I know you are focused on the south and specifically Texas, I’m curious if you’ve heard or seen conditioned attics installed in Canadas colder climates. I understand I would need to follow code and building requirements in Canada but these are often vague. Thanks a lot and appreciate what your doing
Matt has done episodes from up north, including Canada and some of the folks he partners with provide the northern perspective.
You could see Matt wanted to finish the video off with“ the Build Show “ catch phrase. Lol must feel wrong not to say it.
My attic above the living part is conditioned with spray foam. My attic above the garage is vented, I hate it. Our house stays very comfortable all times of the year. Our garage and storage above it gets very hot and cold.
Since we built 3 yrs ago, we've delt with different issues. A big concern is leakage. We have a drip that comes through the foam, but have no clue where its coming from. There's no vents, or pipes within several feet of where its dripping and none directly up front it. I'm concerned it's going to rot the roof and ruin the foam. My builder said the vents in the garage are adequate for air flow. But the attic above the garage is suffocating during the summer, with zero air flow. My conditioned attic is somewhat questionable. No air gap, no space to stop radiant heat. The foam was sprayed directly to the zip sheeting where you could see the nails from the shingles.
We paid good money to have our house built but we ourshelves aren't builders so we didn't know what should be or shouldn't be. Now that I'm taking a look at how our house was built, so many doubts and concerns have come to light. It's a nice house but I'm concerned about what I'll have to deal with in 10-20yrs.
I would be interested to know how much the roof cost on Matt’s house because all this layers should pretty expensive.
It's way overkill and he will be dead and probably the next tenant as well before they recoup the cost.
@@christopherhorne8665 Given all the different suppliers sponsored him, he recoup the cost just fine
Contractors make ungodly money, it’s hard to lose money. I’m a union electrical contractor and extremely well in a very small market. Texas is great because you can charge top dollar and labor is very cheap. It cost me $85 an hour to put journeyman to work and in Texas it would cost me $25-30 and they price a job the same as I do. That’s why the Bible Belt sucks ass
Must be nice to have a limitless budget 💸💸💸💸
Question - I am building a cottage in Canada, Gatineau QC so we will be exposed to both hot and cold extremes. This is a 4 season cottage and I will be using a metal roof. The plan is to have half of the cottage as a cathedral ceiling and other half as a flat roof/ceiling above the bedrooms. I will be using a 5/8" OSB decking with ice and water either on the entire roof deck or at least 36" from the eaves. I plan to use 2-3" of closed cell foam spray on all of the walls and ceiling. I was going to add some 1x3" strapping on the roof deck to screw the metal roof in to. Thoughts?
Thanks
A design shown elsewhere would just add 2 layers of foam on top of the sheathing with the seams offset and a small air gap above the foam. Various ways of achieving the air gap. Don’t need to add another layer of sheathing.
I'm a bit confused. Is there a sheeting that goes on roof trusses first before the insulated panels?
If I'm building a house with an insulated attic space and a metal roof, what's the best way to insulate that when cold is a bigger concern vs. heat?
Trust me. You can’t afford anything Matt has ever recommended. The roof he’s describing would cost fifty grand.
Yes. Sheath the structure. You don’t need to add the second sheathing. There are others episodes showing this. Do add the air gap one way or another.
If you condition your attic does an asphalt shingle roof still need to be vented or is that just for metal roofs?
Asphalt shingles by nature because of the material and the suns rays will cook itself to death. So venting to try and control the temps or have a cooling process will help them. But the monster in the room is the material used and asphalt shingles will always have that down fall.
What is the best way to condition an attic with new metal roof already in place. There is no insulation under metal. No ac unit in attic. I was looking at Owens Corning membrane against truss and blown in in membrane. Should there be ventilation soffit to ridge vent. I’m in center nc
There's eagle shield. Look into them. You're kind of stuck on that assembly imho. Matt has the metal vented above the lid assembly essentially. You won't be able to get there as it is.
Spray closed cell foam on the underside of the roof.
I need you guys here in Rockaway Beach Oregon
How insulated should the floor joists of a conditioned attic (or the ceiling joists beneath the conditioned attic space) be, relative to insulation at the rafters if this isn't going to be a living space. Also, should there be HVAC vents in a conditioned attic or is the heating/cooling of this space intended to be achieved passively through the floor?
My concern is that if the floor of the attic is insulated, and there are no HVAC vents in this space, then wouldn't any floor insulation (ceiling below) effectively prevent passive climate control? Especially if the floor insulation R-Value is close to or greater than the Rafter R-Value, then am I correct that the roof would be, effectively, leaking energy faster than the passive transfer through the floor?
On the flip side, if you were to have HVAC vents in a non-living space, it would seem like a waste of energy, though I could definitely see how it would improve the feel for the living space below or adjacent, but again, it seems like sufficient insulation would be a much more efficient way to achieve this.
I get that my thoughts above seem to indicate a logical conclusion: Little or no insulation in the floor, lots of insulation in the rafters and passive heating/cooling, likely with no HVAC vents in the attic..... But..... I am asking the question because my home was built in the 5190's, it has a vented attic space with 2" rafters and 2 inch joists between the attic and the main floor. Id really like to convert it to a conditioned attic but as a DIY'er, I am very concerned about my ability to sufficiently airseal a 70 year old space that wasn't initially executed with that in mind. I feel like I, as a DIYer, am more likely to achieve an effective airseal between the living space and the attic than I am between an attic (that wasn't originally built with airsealing as a priority) and the outside world. Or am I overthinking things?
We’re in similar boats. I love the idea of these pre-built panels to get exterior insulation, but it’s going to take a lot of reading and reassurance that I’ll be able to create an actual air seal for the interior space. Additionally, the roof itself can vent through the ridge.
For retrofits, it seems like cutting all the rafter tails around the roof and resealing everything as a continuous layer is the starting point. Clip-in new overhangs with an insulated, air permeable ridge vent Aiming for Risingers Monopoly House (straight from Joe Lstiburek mentioned in this video)
As the DIYer, this seems both daunting, expensive, and hopefully a good time haha.
To your point about hvac registers. I’d think a really well sealed and insulated conditioned roof/attic would take very little energy to maintain consistent temps around the house. It would require blower testing to see how leaky it is to get a load calculation.
From what I’ve read, insulation on the attic floor is not recommended when roof is insulated. Why don’t you spray foam the roof which doubles as air barrier? Matt Risinger and Joe have a video and article “Ping Pong Water” discussing the air conditioning of a conditioned attic. In short, yes, you should in climate zones 1-3. I live in zone 4 and will also condition the attic or use closed cell spray foam.
I'm building a roof with 11-7/8" I joist that will be spray foamed. On top of that I'm going with zip panels, taped and liquid flashed, and then 1×4 furring strips and a metal roof. Would this be adequate in zone 5? Thanks
Interested. When are you starting? Shed roof?
@@averageliving4Life I have the roof rafters up and working on my gable walls
It’s probably too late to make a difference for you, but would probably have been more cost effective to reduce the amount of foam inside and spend it on 2 offset layers of foam sheets on the outside. Less expensive and reduces thermal bridging.
Honestly buggest benefit of a conditioned attic, is an entire new floor of space, for storage etc, for almost no money.
Huge win.
How does metal roofing do with hail, like we have so much of here in Colorado Springs?
Depends on the gauge.
29? Not very well.
24-26? I think it’s good past golf balls. Class 4?
22? Bomber
My roof had styrofoam underneath metal roof deck but no decking to convert roof into shingle roof. My question is the previous metal roof had a continuous ridge vent. Now the roof contractor says it is not needed because of the styrofoam underneath the roof deck. I don’t know if I should take their their word for it.
If you have sufficient insulation in your roof system, you don’t need to vent the attic. Just make sure you have enough with no gaps and minimal thermal bridging. You probably need another layer of foam with offset seams.
Thanks again
Watching Dr Joseph Lstiburek He talked about this. I guess since your in the south you don’t need to worry about snow or colder temperatures like California.
But is it really beneficial to AC the attic. I can see that. Making it another room if you made the height big enough. I hate crawling. The kids definitely love it
So the 1x4 is your vapor barrier. For air circulation is like having a vent correct
That’s one way of venting. There are several.
The 1x4 creates the venting not a vapor barrier.
The only thing I don’t like is using gable vents and ridge vents at the same time. I don’t know how true it is but I feel like at the end of the Gables instead of pulling air from the soffit and just circulates right from the gable vent up into the ridge vent
You don't use gable vents and ridge vents together. Venting needs to come up from the soffit and through the ridge venting
@@ckstd yeah exactly what I said
Just curious, when you showed the roof from above, you could see different colors of black....This seems to be common in the world of metal roofing which makes me afraid of getting one...Do you carry a guarantee that the entire roof will be the same color?
Dumb question, I'm sure but why doesn't the roof in this video have penetrations for plumbing venting, etc.?
This roof does have a single pipe penetration. It's behind the tree in the shot with Matt and I. -Thad
@@TheMetalRoofingChannel wow. Code is ok with that I take it I’m new getting into this since covd hit. I finally walking away from 32yrs of work to start my own business. F California. I’m done. In California I swear. Permits and the hoops you must do is a joke
If Matt Riesinger recommends something, the average person can be sure he can’t afford it. Matt thinks everyone is rich.
The Build Show has a couple episodes that touch on this; ways to avoid roof penetrations. All the plumbing stacks can definitely be combined. Just need extra pipe to keep them rising. There are also ways to get around venting dryers and such through the roof.
A semi-related comment: noting that combustion appliances are vented through PVC shows that it is safe to pass combustion gasses through PVC, with little concern for temperature or Static Electricity (more of a concern with woodshop dust collection, but pre-emptively pointing this out). Why don't we use something similar for forced air ducting, especially since a large percentage of air and energy is lost through duct leaks? Of course we would never allow a combustion appliance to leak air in to our living space like a typical HVAC duct does, which is why we don't duct these appliances the same we we do HVAC air. So why do we accept our HVAC leaking conditioned air in to places that waste energy (such as unconditioned Attics)? Why not treat that air the same we we do efficient combustion appliances? With the move to heat pumps and more efficient carbon-based heating, the air temperature from an air handler will not get to a point where it is a danger to PVC (water heaters regularly supply temperature much higher). Why don't we use glued PCV ducts, similar to Water, Waste, and Combustion venting? Would love to hear thoughts from y'all.
Leaky duct work is the key. HVAC installers absolutely need to do a better job installing the duct work in the attic. If the duct work doesn't leak, you can cover it with blown insulation and the pipes won't sweat.
SEEE YA NEXXXT TIMEEEE
I found a bat inside a ridge once when I was roofing hahahah
Vented attic is a must to suck out the heat. Solar fan will be good because it does not have that much power like electric one to suck out the cold air inside the house. Wind turbine will also help & should installed more than one.
Most people don’t have the money to put metal roof with the insulation between like in this video so ventilate the heat out of the attic is a must, period. The attic need seal if use solar exhaust fan or electric
The attic doesn’t have heated air that needs to be removed if the roof deck is insulated. Period.
How can I find someone that builds this way in SWFL?
Sheffield Metals can help you out with some references for metal roofing contractors specifically: bit.ly/contact-sheffield -Thad
How about Treasure coast South Florida? Palm Beach, know anyone who’s installing GAF solar shingles? We need to reduce the heat.
👍
Spray a permeable membrane before the foam.
You've had all those critters in your attic? Someone didn't do a very good job building that home. The only penetrations into my attic are plumbing vents, the continuous soffit vent holes and the ridge vent. There is no gap where the roof and facia board meet. None of the critters you mentioned can get in through those areas. I have a vented attic with one of my ac units located there. I have three more HVAC units in the basement. My house is an all brick and stone story and a half with full finished basement. I used rockwool in the attic and walls. I spray foamed any attic penetrations and I have a styrofoam jacket over my attic stairway. I used Huber Zip on the wall sheathing with tape and liquiflash and Huber Advantech on the roof. I use Huber liquiflash to seal where zip meets top of foundation wall. I used marvin fiberglass windows. I have no bugs and really low heating/cooling bills. What happens when your closed cell sprayed non vented attic develops high humidity in the ridge. Yep, you get rot. I spend the money making sure my duct work is tight and I have more than adequate blown rockwool in the attic. I'd much rather save the money spent on closed cell spray or open cell for that matter and use those funds to install premium windows and ext doors.
Did it creep you out when he was just staring at you at the begining
All Roofs could eventually leak, good luck finding roof leaks..and when u do plan on major issues once u find it..
Should have started out with a MICH lighter colored roof.
There are benefits, though Matt also addresses in other shows the difference and still superior performance of black metal over asphalt.
Thatch kicks all this new age BS, all over town
Why not show a roof in the background without black mold on it. You’ve got to have attic ventilation in hot humid climates.🤦♂️
Vented attics are dumb? Why don’t you mention the price difference between your attic and a vented attic.
Would be more educational if more photos and videos were shown of products and install instead of watching you two gentlemen have a conversation about it. Showing is always better than telling - and there is no value in watching talking heads talk about something that could be shown and demonstrated.
We call this a vented nail base in ohio
Good info, Dustin! -Thad
i hate to be this guy. what they are having put in that roof for a 50 year roof baffles me. my home was built in the 60s, it's not insulated very well but vented. Replaced the shingles 2 years ago the roof deck looks brand new. i mean i had about 4 grand worth of shingles and did it myself and my roof deck almost 60 years old and cost 4 grand to make it last another 20 easily....
i know it makes sense building wise, but matts roof with that many details and what he had to put into it...probably 40-50 grand. it better never need another roof
Construction costs have got to be astronomical, with a double roof system, any savings from HVAC from keeping your ductwork cool would be negated by air conditioning the entire attic. I'm sceptical, our laborers here in Florida do not have the talent to build this. Attics are not status symbols, plus conditioned attics can contribute to roof rot. You can keep rodents out of a traditional roof.
As much as I enjoy watching Matt's builds and learning about building science, you need a lot of money to buy what he puts together. Ignoring the weight and engineering costs introduced in a retrofit like this one, if I wanted to do something like this, an asphalt replacement with my current insulation will run ~$15k or $600/square. A standing seam metal roof would double that cost. I can't find the cost of these Hunter Cool Vent panels, but building something similar would run about $10k in materials cost (ignoring labor). All in all, $40-$50k for a roof alone. That's only going to work in very HCOL areas and I've ignored the additional equipment like an air exchanger and other stuff that would be necessary for the redesign to work.
It all comes down to how long you'll be in the house. 5 years or so? Why bother with a conditioned attic. Just do the minimum to keep pests at bay and then let it be someone else's problem. If you want to live your life in it and pass it down, it's a totally different cost/benefit equation, because all of the rodent, etc. problems tend to compound over time.
Your attic is a zoo.
The only dumb part of a vented attic is putting HVAC up there. Sure, if you can spend >$10k more and get tons more storage space by doing this. But keep in mind it will not be saving you more than $30 of electricity each month compared to just putting the HVAC air handler in a well insulated space like a basement, purpose-built shed or interior utility closet.
Lucky you, you have a basement, a place that's convenient enough to build a she'd, and a spare closet!
Unfortunately for me,the attic is the best place for my HVAC ducting, and the roof-mounted A/C unit frees up patio space (and reduces compressor noise!) too.
Conditioned attic should not be called attic, it becomes part of the house , and should be suitable to be used by human . Think about SIP modular houses
Well I clicked the video to learn more about closes system attic and listened to a guy talk about his root being vented. Great waste of time.
I completely disagree with your closed attic strategy. The science does not support it.
If the attic in this house is conditioned... why is the soffit vented? Shouldn't it be a flush hardy or densglass and have zero ventilation?
To me, that's the whole point of an airtight house with a conditioned attic?
I'm confused, as a novice.
The attic is completely air sealed, the air is just circulating under the roof decking, which is above the roof air barrier