Building a BETTER attic - Unvented + Conditioned attics 101

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[@BrightAngel007]

We so need some videos on taking an attic like you had at the beginning and having it converted to a conditioned attic.

[@LukasEragon]

yeah this would be helpful to me also (doing a renovation not a new build)

[@CertifiedMailSignatureRequired]

try this old house - they've been rocking it before youtube

[@handleuponit]

Good idea. I’ll post one on a conditioned attic.

[@юриймаслихов]

This is a valuable addition to my woodwork collection kzbin.infoUgkxbnOKZBE4evMO5V2vroHeCjq6d_MV6wJO I still will rate this woodwork plan as the best in my reference library. It always seem to stand out from the rest whenever you go through the library. This is a masterpiece.

[@bigredwag]

Consider maybe a vid on how to convert a vented attic into an unvented conditioned attic?? If that even makes sense 😆

[@seannewton93]

Yes please my house was built in the twenties and I would love to see what it takes to do the conversion

[@RobyWanKenobi]

That would be great!

[@danielbuckner2167]

You will have to wait until a vendor will sponsor that video.

[@patrickknapp5867]

Yes I agree. I know how but there still are tricks and questions I have

[@cinaibur]

Absolutely this! I installed a new 30 year roof with a ridge vent several years ago, and now I'd love to seal it without needing exterior roof work. Can I seal the soffits and the ridge vent from the interior before insulating?

[@OmarReyes-pm3fr]

Im a HVAC TECH in south Texas and those conditioned attic spaces are lovely

[@niccolodeparmapanini2036]

Its such a disappointment to have a huge attic only for it to be unusable due to cheap lazy design.

[@AD-1138]

Maybe you can answer this! I cant find the video....yet....of the installation of that conditioned attic....whats with all those smaller white ducts?

[@SBC97281]

@@AD-1138 The small white ducting is for fresh air, it is in the video, but the go over it pretty quick.

[@handleuponit]

@@AD-1138 small white vents are bathroom vent fans.

[@AnN-py2em]

The thing I appreciate most about this video is how serious this man takes his foam, his job, and the willingness to spread his knowledge. It feels like it’s getting harder to find people that take so much pride in their livelihood.

[@staugustinebackwater]

Here’s the issue with unvented attics. The home will self destruct in the absence of electricity (unvented attics REQUIRE air conditioning underneath constantly). Many homes in Florida that either went without power due to hurricane or foreclosure filled up with black mold. Most had to be stripped to the framing to repair. A vented attic is self-drying without power so for our off-grid ready home an unvented attic would have been a horrible choice. I like your videos but when you omit all the cons while touting the pros it seems like a sales pitch.

[@MrSloika]

Yup, in a high humidity, high temp area, this requires continuous AC. Even a short interruption of AC will end in disaster.

[@bigd7355]

I'd rather deal with that by having a backup generator than deal with the nasty vented attic which will definitely have mold anyway. Vented attics are disgusting.

[@staugustinebackwater]

I have been in construction for over 30 years and have never seen a vented attic full of mold in Florida, which by the way is probably the most humid state in the nation. A vented attic is designed to be self drying, and has worked for centuries. Unvented attic’s are new, and require all of your modern conveniences to be functioning perfectly in order to keep your home from self-destructing. Unvented attic’s have their benefits, but people need to be aware that they also require maintenance. We have a back up generator. But even with our 1000 gallon tank, it is not an unlimited supply. Just during the last hurricane we were without power for over two weeks. We have solar as well and are prepared to go for extended period of time, but air conditioners are too power-hungry to use if you were going to be off of the grid for more than a couple of weeks.

[@MrSloika]

@@staugustinebackwater Yup. I live in New Jersey, which has summers that are as humid as Florida. I live in a one hundred year old house. No mold in the attic.

[@kevinlopezobrien5366]

@@bigd7355 seems like your attic venting is insufficient then. Might be blocked up with insulation. Does your attic have insulation vent baffles installed?

[@SlooFoot]

I think what would be even better would be to build a house around this house and then condition that house as well as the original house so that the power bill on the original house is lower

[@rockjockchick]

Lol

[@DonTruman]

Nope, too expensive. Better to build a smaller house inside the existing house.

[@McTwistedTwisties]

@@DonTruman yo dog I heard you like houses

[@schtinerbock4570]

unfortunately that will NEVER become standard with our current builders unless it is mandated which it never will be.

[@xythiera7255]

American hows building yikes .

[@alfredhermansen4787]

He never mentioned the cost. The average American can no longer afford to build a house as it is, much less one built with a new mandate requiring an attic like either of these.

[@ffbuilders8139]

Never say “never”. Energy/building code is constantly changing. 10 years ago most people would say the same thing about requiring solar. Yet here we are. California mandated solar on new residential construction in 2020.

[@jolandafrijlink6103]

As a dutch person and daughter af a builder i think americans houses are flimsy and not durable.

[@jeffraber9110]

@@jolandafrijlink6103 I'm sure as a Dutch person and the daughter of a builder you know all about tumescence

[@finalf137]

If you're looking for any existing houses to do a conversion to unvented attic on, I'm in Round Rock and would gladly volunteer as tribute.

[@finalf137]

Thanks Matt for the like! Really serious, I have a 4500sq house, built in 01’, super leaky/drafty, all three 3 old r22 ACs (1, 2, 2.5 Tons) in the attic. Upstairs attic access through ladder & walk in door. Upstairs gets way too much heat gain from the attic, you can just feel the difference walking up the stairs. Both up and downstairs have high humidity in spring/summer, ~60-65%. The solution I’m looking at is spray foam/seal the attic (suck up all the fiberglass, bug, droppings), but then all the appliances will need to be swapped out for sealed combustion or maybe switch everything to heat pumps instead. If going to heat pumps I wonder if I could replace the 2 of the AC for the 1st floor into 1 heat pump zoned. Both handlers, supply and returns are right next to each other in the open attic, add a whole house dehumidifier in there as well. Totally willing to shoulder the burden on the costs, the savings on my electric bill alone would quickly recoup the project costs I’m sure. It would make a great retrofit home before and after results video. p.s. If I was going to spray foam an attic with vented soffits (Two 4 inch wide Hardie boards with a plastic perforated hole channel down the middle). Would you recommend replacing those existing “vented” soffits with solid soffits, or leave in place and just put foam boards behind it in the attic so the spray foam doesn’t ooze out the vent holes?

[@CaedenV]

A few years ago I re-did my attic in probably the largest home improvement project I will ever do lol 1950s house, and the attic was finished in the 1970s, and the thin drywall and cheap wood panneling was falling apart, and it was always hot/cold up stairs. Gutted everything except the framing, then added a spacer on the roof line, then a radiant barrier, then batt insulation, and then thick drywall. It changed so much! Still need AC units in the summer, but much smaller units keep up well even on medium where we used to have much larger units on high all summer. Things are quieter, cleaner, less humid, and everything is working really well. Next step is figuring out something for the AC/heat up there. Heat rises, and that is the only place to escape to, so it stays comfortable in winter, but there is a lack of air flow/exchange, and during the summer AC is absolutely required. The rooms all have HVAC supply vents... but no returns. Our HVAC is from the late 80s, and it is kind of a miricle that we havent had any issues with it yet, so we are saving up to replace it as the next big home project... that that will be a doosey, but I wont do that one myself. Hoping to move the HVAC to a different location in the basement (what use to be a garage that is walled off), and re-route all of the supply and return vents in the whole house to make more sense and work better. Should be the last step of 'functional' changes to the home before we go nuts with purely aesthetic changes to finally make our old 1950s wrecker look as nice as it feels to live in since I have done so much work on the electrical, insulation, and water management aspects of it. We have the biggest home on the street, and the lowest power bill, but we keep the house at 70* year round while most neighbors keep things at 75 in summer, and 60-65 in winter. Been a lot of work, and it is nice to feel results. Cant wait to make it look nice and 'see' the results.

[@1ronhall]

As a non-trades person, but an enthusiastic home owner, I’ve always thought our traditional attic build methods was very underwhelming and both the sheathing materials and roof insulation always just made more sense. Thanks Matt!

[@chrisedward18]

Looks great. Here in South Texas we look at all things depending on budget. So we use radiant barrier sheathing with a combo of poly to keep attic cooler while staying in a decent budget.

[@Fedgery007]

Large builders will never do this because the other way is cheaper. And they will build with the cheapest crap they can get away with. B

[@TheEngineerd]

Yup. I biked through a neighborhood under construction. $500,000 - $1,000,000 houses. I can't remember the name of the product, but the housewrap was definitely the cheap stuff. Type of material that would wind up in Matt's pet peeves video.

[@jblyon2]

@@TheEngineerd There's some relatively new premium condos near where I live, all $500-750k+. One was for sale recently with pictures of the mechanical room. To quote Steve Lav "what a flippin' joke." Just barely good enough to pass an inspection. I feel bad for everyone that bought them, because if what you can see is that bad, just imagine all the stuff that's covered up...

[@tylersmith293]

That’s great if you’re building a house with a high budget. But what about everyone else?

[@xcyron]

Rockwool is cheap, you will probably make the money back in saved energie. Insulating the roof is the most effective way of saving energie you can do in a house.

[@agoniaXdunya]

What are you even doing here, pheasant.

[@richardroy61]

I used spray foam insulation when I built my house 14 years ago. At that time the cost was about 3x the cost of traditional insulation. However, in real world numbers, I got the difference back in the first 7 years.

[@sw3604]

Get a 3d printed house then.

[@AD-1138]

Think of it this way, would you rather pay more up front or A LOT more over the life of your house? I mean AC systems are expensive! Why spend the extra $$ on a central AC and not just do cheaper window units?....that you will have to replace a lot sooner than a central system plus you now have more of them to replace... It all boils down to where you want to spend the money.

[@trevor61396]

You should definitely cover the importance of having ERV in a sealed up house. I’ve heard a few stories of people sealing up their house and ending up with unsafe accumulation of carbon dioxide because there is no fresh air coming in, which can have serious side effects.

[@swingset1969]

Radon is an issue in homes like this too in some areas.

[@Aepek]

0:24 Hot, that’s an understatement if ever Matt. Live in Central FL and gotta say, when doing a project and time to get into “attic” crawl space…..we do rock, paper, scissors….or draw straws; no joke. Last thing we wanna do during the wonderful “summer” season here in Florida (or what we call it, “Hurricanes, hot, & hell season”) is have to go into the attic/crawl space and do work. Even makes it worse if gotta gear up with PPE🥵🥵, it’s so bad. The pic here is pretty much the typical style, but so much worse for most houses around “us”. We do get lucky once in while and find an attic area where can actually “stand” a little, and move some what around; compared to the normal slithering on stomach and crawling below rafters/framing, NAILS, ducting, and so on. 1:29 [We] all need to start building houses LIKE THIS; as it’s SO Much better, imo. Can actually have access for repairs, running a wire or something etc…, walking and standing up, and not dying of heat exhaustion…. This is such a beautiful attic 😢, so Beautiful, that wish it was My House. Great Vid, and can’t wait for your hidden door vid of your “real remodel”, as love all your hidden door vids; and b/c if your channel, started using Sugatsune and Soss hinges for doing our own “hidden doors”👍🏻

[@rustedoutwrench]

Up in the nothern states at least near me its called a hot attic because it's heated in the winter

[@nfv8865]

As a mechanical engineer working in South Florida, I am beginning to see some major problems with mold growth inside "non-vented" unconditioned spaces that where created by using spray foam insulation. Remember that there is hot humid air inside the house (doors opening, cooking, taking a shower, people) that needs to somehow filter to the exterior. With the use of spray foam, all of this hot humid air gets trapped. When it reaches the dew point, it condenses, turns to water and gets the surface wet. This is just standard physics. How is this solved?? I am still trying to figure it out. If an attic is hot? Who cares as long as you have enough insulation between a hot area and a cool area. The same with wall insulation and double paned windows. So think of it this way. How do you remove moisture from the inside of an igloo cooler? You have to open the lid. When I find a solution, I will post it.

[@brayanmartinez5434]

Keeping it 100% real, I’ve been doing contracting for years now and I can’t even imagine customers wanting to spend all that money. 4” of close cell your looking around $5-$6 per sqft depending on the area and each bucket of costing is $300 each. In Texas you do not need 4” of close cell at all. In Canada we’re temperature goes under 0 use 3”. It’s amazing what their doing but way out of the budget of average Americans.

[@robbiewahl9860]

We do need the 4” (and more) in the south and southeast except for opposite reasons as you. We want to control heat and keep the a/c where it belongs. Building code in my part of Alabama requires R-30 or better. Biggest problem with this conversion idea is roofing material and warranty. Most materials except membranes and some metal roofs require backside ventilation (especially shingles) to prevent excessive ware on the asphalt plys and melting of the roof products and coatings. It’s also a problem with water vapor (depending on the roof type). We’ve done exactly this type of thing but have to use a ventilated nail base or put metal on furring strips.

[@27photogger]

Robbie Wahl roofing membranes as in the peel and stick membranes?

[@hailexiao2770]

3 inches of the best spray foam is maybe R-22.5, which is terrible for a roof in Texas, much less Canada.

[@hailexiao2770]

@@drlava641 Put a layer of cedar breather between the deck and the asphalt shingles, in effect venting above the deck instead of below it.

[@robbiewahl9860]

@@27photogger no, I refer to commercial membranes such as TPO, EPDM or PVC. The only peal-and-stick that, I think, is appropriate would be a Modified Bitumen type and you’d have to check with the manufacturer.

[@dr.emilschaffhausen4683]

Now tackle the stupid vented crawlspace in the southeastern US.

[@charlesterrizzi8311]

Worst idea ever

[@aintquitewright1480]

Show us some FLIR video of these attics on a hot sunny day.

[@davidhoover2446]

I have a flir. Pretty cool product. On a hot sunny day in FL with radiant barrier my attic runs 100 degrees. A lot better than our last houses.

[@aintquitewright1480]

@@davidhoover2446 Yes. I got the FLIR attachment for android. Texas 110 outside 129 in attic before radiant barrier, now the attic is about 3-4 degrees warmer than outside ambient. Keeps my duct work in the attic much cooler.

[@xanthanx]

@@davidhoover2446 100 degrees is still way too hot.

[@chyraxion]

wow thats just amazingly beautiful.. hell i could live in that attic

[@paulo7200]

The rockwool just looks nicer.

[@thomaslbane]

Costs more, though…. So does the framing…. Especially if you use SPF (double-so if using intumescent coating)…. Oh, and the roofing won’t last as long because it gets hotter with insulation beneath it… And SPF prevents drying to the interior so small leaks in the roof are a MUCH bigger issue because the water gets trapped between the impermeable roofing and the SPF. So, yeah, it’s “better”…

[@jakebredthauer5100]

@@thomaslbane Maybe Matt "needed" to publish a video and didn't have time to think it through. What about cost to build, cost to maintain and cost to operate? More flooring, more stairs, bigger door, difficult insulation installation, more difficult shingling a high-pitched roof.. He should do another video addressing the issues you identified.

[@27photogger]

Thomas Bane does it really have heat issues causing roof leaks sooner since the roof can’t breath as well with the spray foam ?

[@jakebredthauer5100]

@@27photogger Asphalt shingles are sensitive to heat, steel not so much.

[@cybermanne]

Great video as always. One thing I'd be interested in when it comes to spray foam is those horror stories of foam that never "cured" and are off-gasing some horrible fumes that makes the kids allergic and sick. It would be interesting to know what has been going on in those cases, and what they did wrong there, and how to avoid it.

[@hsantillo864]

I'm in that mess now with open cell on the walls and roof, plus the contractor sprayed the heck out of everything, the attic vents in the gable, the roof ventilation fan. He claims it's a non venting attic, of course he turned it into one and created a sauna!!! The off gassing when it's hot out is horrible. It stopped my kitchen reno now that we had to pull off the damp drywall and ceiling. Not sure how to best remediate this mess! Need advice.

[@cybermanne]

@@hsantillo864 I have no advice unfortunately. Only condolances. Hope you get it fixed.

[@davidtyndall8880]

Why aren't you using "saddles" on the flex duct strapping? You know that over time the web strapping will crush in on the flex ducting and restrict the air flow.

[@RevolverOcelot79]

Agreed

[@HandlesAreDumb_111]

Guessing it's not the flex that you think it is? They make insulated rigid duct that looks identical to flex until you press in on it.

[@terryherrera5252]

BUT !!!!!!! This attic !!! I never above 80* !!! My problem is COST !!🥵

[@intender4good]

Me: reading close caption “You know, most addicts in America look like this” Me: sees white guy in the attic. Me:Yep

[@mahnamahna3252]

🤣🤣

[@mangos2888]

🤣🤣

[@craigmellott6339]

When I hit the lotto Matt will be building my next home

[@RemmikRotus]

Hopefully it would not take over 2 years :)

[@judefuselier]

When I hit the lotto I'll be building my own house

[@ChiBr33zy]

I would hate to be the roof that might have to replace bad roof sheeting if a leak forms. That spray foam seems like a good idea, but its makes changing out bad wood a complete bear to replace.

[@danielhoughtelling9721]

The biggest practice change is trusses vs rafters. Newer houses use trusses because they are faster to install. Most people who can afford on site cut rafters do so for the extra attic storage space.

[@reaperthemad8731]

Also, if you're in an area where high winds can be an issue (tornadoes/hurricanes) check what happens to the prefab truss roofs.

[@mitchjohnson4714]

Maybe they can do it with attic trusses.

[@johnlee7085]

There are a variety of truss designs. Some easily allow for use of the attic space.

[@tobiasnachname6358]

Nice to see that the US is slowly adopting the standard we have had in Germany for 20 years :>

[@dryfly2000]

I agree the typical American home builder doesn't"t give crap about efficiency. Nothing here has changed much. I wrapped my house with Tyvek 5 years before builders began doing it here in Salt Lake City.

[@mfam2371]

Yea glad to see Germany adopted the standard we had back in the 40s

[@matth7621]

I don't think people have necessarily been building "dumb", just cheap. If I could build your attic at the same cost as traditional attics, everyone would have yours.

[@a..d5518]

for houses built in the 60s, 70s and beyond remember that a lot of the current methods, technologies and materials were not known or available unless you were loaded. So cheap was not a purposeful way but rather the standards of the day.

[@jameswalker590]

@OpenYourMind Do you have cost comparisons to show? From what I understand, ductwork leaks about 20% of the produced heated/cooled air. Lets say you spend $1000 to produce the conditioned air (mine is less), that's saving $200 per year. How much would spray foaming the underside of the roof cost? If 1 inch is R7 and $1.50 (on the low end), for a 2000 sq ft house (the roof would be more sq ft because of the angles, but let's just roll with it). 2000 sq ft * $1.50=$3000 for 1 inch (R7.1 per the guest on the video). Surely you're gonna do more than R7.1. To get Matt's R50 he mentioned would probably be 4 inches of spray foam and 4 inches of rigid foam on the roof. 4 inches of spray foam would be $12,000 on the low end + the paint they're using which probably isn't cheap. Add the 4 inches of rigid (R10 at Lowes is $28.38 (Call it $32 with tax to make this easy) = $1/sq ft for 2 inches, but you need 4 inches, so it's $2/sq ft. 2000 sq ft * $2 = $4000. So $12,000 + $4000 = $16,000 (not including the extra labor it's gonna cost to put OSB down on your roof over 4 inches of rigid insulation. Your break-even is $16,000 / 200 = 80 years. I'm all for doing my part and I want to save energy where I can, I even l seek out things I can do, but this is much too expensive. You'd be better off installing a ductless mini split in every room. Or you could build a chase in your attic to run the ductwork through and insulate that. I'm likely going to retrofit my ductwork by sealing all connections and then building a chase from Rigid insulation. I'll fill the chase with blown fiberglass.

[@bairdjc]

@@jameswalker590 I'm glad someone did some rough numbers. Concepts like this are great because they show possibilities and get people thinking, but it's far too easy to just revert to "everything else is dumb" mentality. Is the "old way" dumb? Perhaps, but the "new way" seems so crazy expensive to implement that "dumb" isn't so dumb after all. I wish that those numbers were included in the video - however that would also immediately kill the narrative. And for what? What are you really gaining here? A nice storage space (not really livable with all those ductwork penetrations everywhere) and probably save some $$ on cooling. It's up to you to decide if the massive increase in build cost is worth the benefits.

[@charlesrodriguez7984]

@@bairdjc especially when the brits say our windows are dumb or walls or even other stuff in US homes.

[@Bob_Adkins]

Back in the day, insulation in direct contact with roof sheeting was a no-no because the shingles get too hot. A space for passive venting kept the shingles a little cooler.

[@3beltwesty]

The shingle roofing literature mentioned one had to have a vented attic so the shingles say cooler or the shingle warranty was void. The buidling codes too also had plans reviewed to check the number of soffit vents and top vents so the attic was vented.

[@fepeerreview3150]

It depends on the shingle manufacturer. GAF provides warranties even for unvented roofs. Tamko doesn't.

[@toddcunningham3213]

Our local codes require it. Plus, I don't think the way the attics in this video are framed would pass snow load requirements with 2 x 6 rafters on 24" centers and no strongbacks. We typically use 12" TGI engineered rafters for applications like this, but the joist space is still vented.

[@hvfd5956]

I really like what I saw in this video. Very neat technology. I also like that you thought about the fresh air needs. I would not have thought of that need, but should have since I grew up in the days of the gas space heaters. As a former volunteer fire fighter, no or at least less smoke is a big deal. Current trends are to cut a bunch of holes in the roof to let the smoke and heat out so you can see where the fire is. In a house fire with someone trapped, the firefighters had to back out when the FLIR camera showed the temperature at 742 degrees, roughly 4 feet off of the floor. The trapped person didn't make it. As the fire captain said, "no one survives that kind of heat". The open core bedroom doors just went whoosh and only the frame was left. This was a 50 year old brick 3-sides house with typical shingle roofing. That was the problem. With the room temperature that high, the tar on the bottom of the shingles melted and dripped through the sheeting, then burst into flame in the attic - making the temperature that much higher. Once they got the attic temperature down a little, they were able to go in and pull ceiling to finish the lowering of the temperature. The whole thing was out in about 5 minutes after that. As a result of the SMOKE, the city inspector required that the left overs be taken to a special hazardous materials dump. The smoke alone caused everything to be classified as hazardous. If your house catches on fire, please remember what we taught you in elementary school, get flat on your belly and pretend you are an alligator then crawl out. Don't stand up! Your lungs can't handle the heat or the smoke.

[@handleuponit]

Wow. Incredible story

[@ThePurplePupUwU]

One day, when I have a good paying job, and am ready to own a house in 10 or 20 years, I want to have the home built brand new, according to the specifications I want, I'm going to hire you for that project, I've loved all of your projects!

[@ericwotton2046]

I don't have any mechanicals in my attic so I left it vented and put a deep layer of cellulose up there.

[@Dancing_Alone_wRentals]

That is the route I'm going with. Seems like the flaw in construction practices was to not build a thick floor as a ceiling, then add the roof framing. Truss roofing over the years gave us poor insulation.

[@hailexiao2770]

@@Dancing_Alone_wRentals Truss roofing is fine since you're supposed to use the bottom chord as the attachment point for the air barrier. The trick is to build the wall 1-2 feet taller than what you'd normally do and use that space for a dropped ceiling for all the mechanicals.

[@Dancing_Alone_wRentals]

@@hailexiao2770 That is what I was thinking. Seems much smarter and as far as working in an attic vs off a short step ladder, I would rather work off the short ladder installing mechanical along the ceilings. I built a house in Florida and the HVAC guy came in before I had plywood on the trusses. He loved it.

[@vegasheat71]

This is exactly how I want to build my next home.

[@steelyspielbergo]

The most expensive and complicated way to have a low r-value roof. Maybe it's just dumb to have an overly complicated hvac system in the attic to begin with.

[@DavidEVogel]

That would be my house in Tucson, AZ. First time in my life I have ever seen a HVAC system in the attic.

[@lkj974]

Yes, but with no basement or crawl space there is no other choice.

[@SBC97281]

@@DavidEVogel Most of the houses we looked at in Austin and San Antonio have HVAC in the attic. When we redo the roof, I am tempted to mini-spit the whole house and insulate the attic similarly to what this video shows.

[@jonathanlanglois2742]

That's what my attic looks like, but I'm further up north, and my ducts are in the basement. We had a water leak with our roof and if anything, the fact that the attic is properly vented is what prevented further problems (by allowing everything to dry properly).

[@6stringsandapick]

If HVAC is not in the attic, this does not make financial sense. The ROI on that upgrade it 30+ years. Yes I have run the numbers and that's what it looks like. And leaving Rockwool exposed to the conditioned environment is not ideal for IAQ.

[@kadmow]

- re rockwool. I thought the same - cover it in with some rigid boarding - or open cell sprayfoam (and intumescent layer), it will shed fibres - eliminates conductive loops through open fibrous insulation.- Also, remember, people pay premium prices for comfort (or perceived comfort) all the time. No thoughts (nor realworld expectation) for any ROI. 30 years is as good as infinity (most product warranties that long are as good as worthless, as there will likely be "contributing factors" in their failure) - given typical inflation etc, many middleclass people may have remodelled their kitchen and bathroom once or twice in that period (even the attic)- given people don't keep houses for the full 30 years for much of their lives.

[@nicholascooper1193]

Yep, this is for slab houses. My current build has a basement with precast insulated walls, HVAC in the floor, 2x6 above grade walls, and a vented attic with raised heel trusses and blown in R-60. WAY cheaper to build and it'll still be energy efficient.

[@amyschwebke4007]

Purchased our retirement home (built in 1947) - roof is currently a mix of normal pitched roof and some flat roofed areas. Will be installing a brand new metal pitched roof where trusses will be built onto the flat roofed locations so that all the roof angles are same-same (rain gutters to water barrels for gardening needs). I'm thinking the DC315 spray foam would be the best option for the new roof trussed areas. Would love to see a retro-fit video of an older house being updated with these new insulation techniques.

[@jimbo4203]

The most expensive attic ever ! That you cant live in

[@blackberryfarm7179]

Yes problem solved by using cellulose insulation not fluffy fiberglass.

[@AD-1138]

Would you want to live around duct work? lol it is still usable space....I tried storing seasonal decorations in my attic.....a lot of it melted in the Texas heat....sooo, cant use my attic as is, it is literally, dead space.

[@jimbo4203]

@@AD-1138 the money that was spent on a attic like that one you could have made a air conditioned room !

[@AD-1138]

@@jimbo4203 You are obviously missing the point of why they are making the conditioned attic space and how you will save money over the life of the house.

[@McTroyd]

Great stuff Matt!! (Totally not making a spray foam pun. 🤣) Even got the wife to watch! 👍

[@imolazhp11]

Love the idea of a conditioned attic, I just wish there were companies out there that would convert existing attics to conditioned attics. Building a new house isn’t a solution for most of us.

[@Engineer10211]

There are. Get the roof deck and gables sprayed with HDPU foam up to the r-value needed for your region. It's called "encapsulation." I retrofitted the attic in my 1950 house in Texas and it is glorious.

[@imolazhp11]

@@Engineer10211, that’s great. But it seems like a retrofit these days requires the owner to act as the contractor, and manage subs. Spray foaming the attic is only one step. Then an HVAC company needs to come in for ducting fresh air, general laborers need to come in and remove blown in insulation and deck the attic. A one-call, turn-key company would be nice. It’s a business opportunity/idea for sure.

[@Engineer10211]

@@imolazhp11 The fresh-air ducting isn't needed after encapsulation unless the rest of your house is extremely tight already. That said, if you have a gas furnace or water heater they will need to be swapped for direct-vent models but you can probably re-use the roof penetrations for those. I know that insulation companies in Dallas will remove old insulation. And oh yes, I modified my gas dryer to be direct vent (don't tell the inspector) with coaxial venting and a plenum on the back of the dryer. But if you want a sweet setup with a floor, yes, you'll either need to DIY it (or at least a lot of it - I recommend getting a sub for the spray) or hire several contractors. My wiring was running on top of the ceiling joists, so I drilled through the joists and re-located it (I'm a structural engineer, so no problem getting it right). So that's an electrician. Decking would be by carpenter (I did my own). If your ducts are all over the place like most are you could hire hvac to tidy things up or do it yourself. It may sound like a good business idea to provide a turn-key project, but it's hard enough to sell people on the idea of investing maybe $7 or more per sf to just spray their attic. Doing all the other stuff would probably push it to $15. There aren't going to be many takers.

[@KN-jr6tx]

@@Engineer10211 Is your estimate of $15/sqft inclusive of all costs for the conversion? Also, is that calculated by the floor area or the surface area of the inside of the roof and walls? Thanks!

[@Engineer10211]

@@KN-jr6tx I'm totally spitballing that number, but it would be based on the square footage of the attic and yes for the total conversion. So converting the attic of a 2000 sf (one story) home would cost $30,000. That is just a really rough guess. An attic floor isn't going to serve much purpose where there isn't enough height to use that space so the floored area would be smaller than the house footprint. The spray foam would have to be on the entire roof deck and that particular cost would be calculated from the sloping area of the roof, not the horizontal projection.

[@Stewbular]

I was watching a video w a drone shot over house in Canada I saw a house w the HVAC box & all the insulated ducts ON TOP OF THE ROOF

[@imitane]

If the roof leaks and sheathing needs replaced, is it a huge pain to have it “glued” on with closed cell foam? I guess it’s no match for a reciprocating saw, but then it would need to be re-sprayed afterwards?

[@neverknow69]

Nope you just sheet over the old stuff.

[@redfirekla]

Yeah same channel proves this is the worst product for a roof kzbin.info/www/bejne/fmfNmnqBhLh0eNE

[@Mostviews111]

I've always hated the idea of a spray foam roof by the time you would notice a leak the entire roof and trusses would be mush

[@gallamine]

@@Mostviews111 in NC, climate zone 4, most ppl recommend open cell for attics. Spotting leaks is one benefit.

[@srt4b]

@@neverknow69 You sheet over rotted sheathing?

[@jeffreymcdowell3024]

Hi Matt, I am a Dallas resident in a 1980s home. We will be having our existing insulation removed, air gaps sealed, and new 17" of insulation blown in. One thing I have not seen from you is how to convert an existing Vented attic into an Unvented one, including cost comparisons with just adding new insulation. Feel free to reach out and use my house as a demo :)

[@DuncSargent]

You need to be able to put your model railroad up there too!

[@kenyonstewart7120]

Hey Matt, It would be nice if you could cover a framing, insulation, and barrier package for a vaulted ceiling build with no attic. In CA, many homes are pier and beam, so ducts are under the floor instead of in the attic. Vaulting a ceiling is a common home renovation request.

[@mikedandar1171]

I think that would be good for CA, especially with the fires you have out there. An unconditioned, vented attic could easily draw in embers from a fire, whereas, if the attic is conditioned and sealed off, there is no way for the embers to get in the attic. 👍🏻

[@johnlee7085]

The only difference between a vaulted ceiling and the attics shown is the extra framing for the ceiling and the location of the wall finish. Ooops, ductwork too. The insulation is the same.

[@cmb5286]

Matt love the videos, but I’d say the majority of your viewers don’t have this in their budget myself included. When sponsors pay for half your house, it’s easy to put this kind of thing in.

[@tmiranda1379]

Ultra wealthy and government buildings (tax payer funded) is the only new construction I have ever seen with non vented attics.

[@MrTexasDan]

@@tmiranda1379 or sponsored KZbinrs

[@MrTexasDan]

@@JavaZombie No, just the stuff that is of questionable value that he is trying to pass off as the norm, or as "a better way".

[@gloofisearch]

This is how the rest of the world is doing their attics! The US did it too, but that was before we got cheap shit houses we have now. We store stuff in the garage because most new houses also do not have a basement and our cars park outside in the sun and rain. In addition we pay for storage spaces. Overall, we went backwards and pay more.

[@michaelbacile8439]

I have an 86’ rancher in central Florida. By no means was it “efficient”. All I did was add a ridge cap, used batton style insulation instead of blown, decked over the batts with 1/4 plywood, sealed any air gaps in the ceiling with spray foam and installed a fan up there that works on a switch. My house feels so much better and my electricity bill is thanking me as well.

[@Psychobilly]

Great content Matt. I also went back and watched the Zehnder video.

[@billclinton6040]

Building a conditioned attic is essentially adding more square footage to your house. I can tell you right now, if I was going to spend the money to finish my attic like his, it better be livable like a second or third story, not just a comfy space for duct work.

[@trex2092]

Enjoy your high cooling bills while you are at it.

[@trex2092]

Some people just don't get it. What is fun about having your ductwork bake in an oven?

[@NoBody-ro3xj]

Comfy space for your storage, and for the future workers that have to do repairs instead of sweating head to toe.

[@fraidykat]

Do you enjoy paying higher taxes too? Because a finished attic space that is not part of the square footage is storage space that isn't counting against your property taxes.

[@bigd7355]

I'd rather deal with higher cooling bills than the dust, pollen, and mold that comes into your house through a traditional vented attic. Those have major health effects that most people are too stupid to notice.

[@kd7nyq]

In your linked video, I wanted to say thank you for not being afraid of using your metaphor. "When God created our bodies..." It means a lot to hear people being genuine.

[@pastmasterdan4080]

I’ve seen some SIP construction that didn’t require any vents and a small hole allowed for environmental exchange between upper & lower. Fantastic insulation by the by.

[@mekkler]

What this tells me is that home owners are at the mercy of builders and contractors. You have to just hope and pray that they know what they're doing.

[@MrStupidPantsEv]

Seems like that DC315 coating should be applied to attics even if they aren't used, to protect the wood from burning.

[@mwillup180]

I see this becoming a residential building code in the near future. Similar to how exterior insulation has become the norm.

[@koekum2142]

Wow, groundbreaking. Unless you're from Europe, we have been doing it for decades.

[@ImDembe]

@Bob Watters Europe is a very wide term, in Sweden the average isn't even 10cents per kwh. We have't gotten around to install ACs since we have been more keen to keep us warm...the last couple of years however the summers have been crazy in terms of Swedish standards, around 84-90c so i think alot of places gonna invest...that was the best things about being in Florida, it could be 90-100f but when you enter a building you know it's gonna be around 68c :)

[@gabolujan3109]

I’m from Switzerland what do you mean?

[@literalsweatequity]

Amen to the importance of a sealed attic, Matt. When I insulated mine, nobody wanted to believe me that it was going to be 75 degrees in side with 100 outside. Got the proof today! 101 outside, 71 inside. During the manual J calculations I had to argue with the engineer that I wasn't going to have 40% energy loss in the attic because all my ducts were in the conditioned space. And because the attic is my return air "duct" that saves even more energy. My A/C guy and I decided to downgrade from a 5 ton unit to a 3 ton after he saw the results. Thanks for the great videos. Amazing what one can learn!

[@andrewmckinlay2964]

What do you mean your attic is your return duct? You have vents between the attic and house?

[@literalsweatequity]

@@andrewmckinlay2964 The problem with sealed attics is that you get stagnant (and humid) air in them while your return air is passing through it through return air ducts. A truely "conditioned attic would require supply and return ducts to cool/heat the attic. We opted to passively condition the attic by running all return ducts with terminations in different attic locations. Since the attic is sealed it operates like a giant return plenum, concentrating and mixing the return air from the house. The air handler then pulls the air from the attic and recirculates it throughout the house where needed. In addition, this gives us the opportunity to manage the humidity with a whole house dehumidifier and let the dry air in the attic mix with the return air from the house. We have several thermometers with hygrometers throughout the house to verify that this principle works consistently. Hope this answers your question. - Wolf.

[@pattersonlandscaping5621]

wow...jjust looking to convert to conditioned with foam...GREAT INFO...Thank YOU

[@atlantasailor1]

My attic used to go to 130F in summer. I had spay foam installed and it rarely reaches 90F. The electric bill has been reduced by about one third. But the more important thing is that the AC cools the house much easier. From Atlanta… the other benefit is that the attic is much more usable because you don’t temperature extremes. My attic is floored so it’s like adding extra rooms to the house.

[@xxshedheadxx6134]

As an electrician I appreciate this video

[@rubenisenia8702]

All the ways I see on american youtube channels make me laugh because they are so old and outdated so is this one. In the first place, the first way of making the attic, such a waste of your space. In addition, it is always a mess with cables and flex AC channels. Have you never heard of cable ducts over there? Maybe you should come here to see the European way of building. All the mentioned "new" solutions have been used here for years as a standard. For the first roof in his own house, he only uses Rockwool, very good, only a vapour-tight layer is still missing. On a cool evening or in winter, water vapor will condense under the metal roof or against the roof boarding and cause it to rot or mold. It's almost done, now just have to finish it the right way. The foil also prevents the Rockwool panels from sagging, which happens after 1 to 2 years. In addition, the particles that come off the insulation boards cause lung damage with prolonged exposure. These particles are released by just the air moving through space. These plates must always be finished or concealed if it is a room where you can or may come often. If they are the specialists, they still have to learn a bit more...

[@adambert3042]

I agree. The space between the Rockwool and the plywood will indeed cook! I like to put baffles and let air flow along this plane. And yes I also agree that the exposed rockwool is not the best of ideas. Cover it with permeable house wrap or with permeated fi foil.

[@k55f5r]

I used radiant foil OSB when I built my house in SoCal, the attic was 20° cooler than the outside in 100°+ days. Well worth the additional cost.

[@MrWiseinheart]

Can only imagine the price of that today considering the price of normal OSB..

[@V3VoVo]

@@MrWiseinheart thanks to the liberal policies

[@butch8792]

@@V3VoVo exactly every cost increase in the world is directly related to liberal policies

[@Jonasty00]

@@butch8792 yes! I’m glad we’re on the same page

[@Moondoggy1941]

@@butch8792 No, just 75% of them.

[@fwaynedavis]

Having lived in a Texas home with a conditioned attic I can confirm it is an order of magnitude better than conventional. It was proven as my neighbors had conventional with Identical builder. I opted to spring for the initial $$ up front. Result? My heating/cooling costs were 1/3 my neighbors with same size homes (2500 sq. ft). No Dust, no bugs, super quiet, and no dread when handling things in attic. I can verify also the cost upfront was easily offset by energy savings, and no doubt made my home sell at a higher price than comparables due to my ability to prove energy costs based upon actual bills. I will never live without a conditioned attic ever again.

[@williameldridge9382]

Last I checked, doing a conditioned attic increases the cost of your build by like 20-30k. Spray-foaming alone will run you like 10k on a house that size, then add in all the extra building materials to make an attic like that. It costs about $133 on average to cool per month at 2500 square feet (the median house size in the us actually). It's great if your bills are a third of your neighbors, but to make up for that much money you'd have to own that house for DECADES and that is just to break even. To actually start seeing a benefit you'd essentially have your house paid off (with an average 30 year loan). The person that didn't spend that extra 20k-30k will have their house paid off that much sooner as well. You have to think long term here. Yes, that house is more efficient overall, and is in fact an energy saver. But it's gonna need multiple owners and decades to really pull ahead of a traditional attic, and those building the home will have to be able to afford said house. Meaning they either need to put off building longer so they can save up more money and potentially get a better career to afford the higher payments, or they'll be struggling to pay for the house and likely never pay it off before they die/retire. It's all about costs, really. And with the housing market right now, and the cost of building materials, you can double or even triple those extra costs. So suddenly that 20-30k is an added 40-60k, or even a 60k-90k extra cost (depending on many factors including house size). It's all about costs vs benefit and for a lot of people it won't be worth it.

[@fwaynedavis]

@@williameldridge9382 I agree, costs today aren't a direct cost savings. But there a huge thing to ponder. It is the running and lifetime costs. The cost in in today's dollars. 20 years from now the initial amount will be beans, and energy costs will be massive in comparison. Actually it can become a reality much sooner with current political pressures. It adds more than energy efficiany it creates strength, seals moister prone areas (we live i black mold country) and creates a storage area where you valuable dont get ruined by 150+ degree summer heat BTW.. where are you getting those costs for materials and labor? You must live in a non-right to work state where unions rule. Here in TX My neighbor just foamed his place at $2 Sq/ft. Its about 2.5X conventional fiberglass, But nowhere near those numbers you are getting.

[@SyTySpeedShop]

When you build your house with an unlimited budget!

[@scottielewis5136]

I like how he doesn't say what the difference in cost is. Like, yeah that would be awesome... I can't justify that cost when building a house brah.

[@wilburosgoodwormsley]

Exactly

[@chrisgraham2904]

Not possible to achieve the necessary R value without the 4 inches of foam board on the outside, between the deck and the metal roof. Big increase from a standard roof.

[@michaels.ramsey7803]

@@scottielewis5136 its triple cost to build and your monthly bills will double.

[@sw3604]

Better to build houses right

[@jerishigan6567]

As a chemist, I can confirm that the cold gas CO2 sales pitch is hilariously wrong. 😂

[@ptester1]

Yeah, I was wondering about that, too. I think what they were really trying to say was CO2 helps extinguish the fire without being toxic? Or maybe the tumescent paint expands with pockets of CO2? Of course any fire is an oxidation reaction that consumes oxygen, so unless it’s supplied by the fuel some sort of oxygen depletion is going on regardless.

[@jaedodrax7735]

the pitch, it hurts....

[@br2266]

Shhhhh it's a trade secret!

[@jasonsstratton]

burning the paint produces CO2 and theoretically creates a latticework of the the paint material with spaces filled with CO2. this kind of latticework structure is good at insulating things but in order for it to be cold, the burning would have to produce an endothermic reaction and I cant see how that would happen, at least not enough to overwhelm a propane torch,

[@arcanondrum6543]

It's not my field but the unprotected foam is, according to Matt, still too hot but they can touch the burned side of the painted foam. Oxygen fuels fire, CO2 does not. The heat energy created the CO2, stealing heat.

[@RonnyMathewTheNorthStarrX]

As cool as this sounds…this looks unrealistically expensive and resource heavy for an average homeowner/builder. I’m also a bit disturbed by the comments that mention the AC HAS to be running for this to work. That’s a major drawback for a normal homeowner.

[@andrew1532]

I know right. I saw HIS attic and I thought what a waste of mats. I can get behind finishing an attic but not this. There are reasons why these have been done for decades.

[@95thousandroses]

I like Matts stuff and he's a great promoter of how to build better homes. But so many of these things are out of reach of the average home buyer. Basic homes already require a 30 year loan for most people.

[@Michael-ko4ko]

Yes you have to run the AC always. If you don't, its sealed up so tight mold will grow. This happened back in the 70s early 80s homes when they put Styrofoam on the outsides and tapped all the seems. No air exchange and the houses molded to the point of tearing them down.

[@andrew1532]

@@Michael-ko4ko but we now have vents in the roof and eaves of the house that cause convection to stop still air from molding. Plus balloon walls are never structurally sound and never where so house fall out more than ever do this cheap design.

[@allandulles7108]

As if the crazy tubing at 1:22 hasnt scared people off. Youd think he was building a fucking chip fab or some shit.

[@NICKRITZER]

Thought about doimg spray foam for my tiny home...pretty sure after needing to spray paint...i think i'll just do traditional insulation.

[@brad7358]

one usually does the spray foam for a few reasons....and one is to lower the electric bill. we did this to our first house along with other things and our bill dropped from $300 to $150. other things that were done were new windows and ac....but having an attic that doesnt reach high temperatures is going to save you money each month. we recently sold that house and bought another one and we are going to do the same thing again with the spray foam.

[@chad3076]

Yea, stick with fiberglass. Spray foam is fast and easy but you're paying WAY more for it.

[@brad7358]

@@chad3076 define WAY to much ?

[@KimLumbard]

@Matt V There are even more issues with unvented attics. This kind of approach only works in warm climates that rarely see ice. In a northern climate the build shown here would experience ice dams and water fracture on the roof surface. Matt Risinger usually has pretty good solutions for houses, but this is clearly a climate fail. He should make it clear in the video that this would only work in a narrow climate band, the one he happens to live in. If someone in a colder clime naively followed this build, they are headed for tens of thousands of dollars of damage.

[@oldsteamguy]

yep

[@Capn--Jack]

@@oldsteamguy Totally Untrue - I live In South Dakota and Spray Foamed The Underside of roof sheating for in 2009 - Absolutely no problems

[@glenagarrett4704]

Would like to see a video about attic encapsulation where you use the reflective radiant barrier and air sealing everything between the attic and the conditioned space, to include using insulated light covers. It isn't nearly as expensive as this conditioned method but still works many times better & accomplishes the other benefits over the traditional method you show at the beginning.

[@DorianMariusGray]

I love that he makes this video just for the average consumer(insert sarcastic face).

[@ronmullen8690]

Good video; what if a bushfire was active; what would happen to the incoming fresh air inlet, would it go into safety mode?

[@redactedinformation2813]

Non vented roofing system is Florida is a disaster of epic proportions. The USDA attempted this in tampa on several residential new construction sites. Less than a year and the homes are unlivable due to mold.. great job reinventing the tried and true vented system..

[@froissart1]

Is it possible to move from a vented attic like the one you were in at the beginning to an unvented? How does one remove the trusses?

[@Egleu1]

Trusses are structural you can't remove them without changing the roof joists to 2x8s or something.

[@jaxturner7288]

@@Egleu1 nah shucks, just sawzall the old trusses out of the way. Totally not needed anyway. Easily a DIY weekend project.

[@kipwilson3771]

You start by using real trusses and never using pre-fab pixie styx.

[@jaxturner7288]

@@blaydCA that’s brilliant! Well, obviously a professional has entered the chat. Quite please, I want to hear this.

[@jaxturner7288]

@@blaydCA does that mean I was fooled? Are you not a real pro builder guy? Because I don’t think we can set this guy as the standard to meet as a pro can we? Maybe as a standard for a professional from California?

[@tha073926]

Could you convert a non conditioned attic to a conditioned one? I would love to see a video about that or even better an actual example of one being converted.

[@dustinschmelzle7326]

you can but the thing it if the were built not intending to be contained the roof structure may need to be redone to make the space navigable

[@JRMoritz]

Every time our AC comes on we get a blast of super hot air… we are in Central Florida.

[@DTWCT]

Not the best option, but a cheaper one is to spray foam the ducts

[@tomsterism]

The "weeds" you and your professional guests consistently get into are not just details. They form the very skeleton and frame and BONES of each structure and are, far and away, more important than the obvious, colorful, brainless features on which most homebuyers focus.

[@marcrcbally]

Remodeled a 3 apartment house using only rock wool as insulation for both temperature and sound. Worked wonders, afterwards you could not hear a sound between the apartments while before you could understand any conversation that was above a whisper. Not only is rock wool wonderful to work with, it's not itchy in the least. And as a bonus, it also acts as a fire barrier.

[@VanHalen2TheTop]

We call it the green itch when we use it framing lol

[@johnlee7085]

I loved working with the rockwool on some of our remodeling. Just couldn’t find it consistently. Definitely chose it when I could.

[@RandyCantrell]

Matt, what suggestions would you have for homeowners who'd like to condition the attic on their existing house? Love your work. Thanks for sharing your insights, experiences and wisdom.

[@johnlee7085]

Do it when you replace the roof so you can add several inches of foam board on the outside. Otherwise, you won’t get the desired R between the rafters.

[@michaelmansour6326]

What happens when the roof, flashing etc. starts to leak after so many years? It just rots the heck out of the osb roof sheathing and no one notices it? I understand it wont drip through. Sounds like a recipe for disaster??

[@justinlassiter7671]

he most likely has an impermeable layer on the roof decking between the metal roof and sheathing. it can only leak where fasteners penetrate. from there you just give the water a place to go.

[@fepeerreview3150]

Probably shouldn't be waiting for leaks to rot through your sheathing and start staining ceilings. It would be better to inspect the roof yearly and replace/repair flashing before the flashing fails. In short, routine maintenance can save a lot of cost and headache down the road.

[@benjamindobalina7493]

@@fepeerreview3150 Explain how if you have to do "Preventative yearly inspection" on your wood deck, sandwiched between plastic foam from underneath, and you shingle or metal, (especially the latter) on top, without ripping one or the other off? just curious

[@fepeerreview3150]

@@benjamindobalina7493 If you'd like to know more about how to inspect roofs and flashing you can learn far more about it from studying the material available a NACHI, which is the Association for Certified Home Inspectors. They've got lots of good material there. I'll link to one of their articles. There is plenty more. In my previous comment I had in mind all the visible flashing elements, gutters, roof-to-chimney, vent penetrations, etc. Those are always the most likely spots and the first to go. Look for signs of corroded GSM, poorly done caulking, things like that. If those visible elements are checked regularly, that will prevent a lot of common problems. Most people don't even bother to clean their gutters often enough, let alone pay attention to the roof. "Out of sight, out of mind" is very easy with a roof, and sure to lead to costly problems that could have been caught and dealt with much earlier and more cheaply.

[@ernieforrest7218]

Well Matt conventional roof rafters have been the standard method in many parts of the country since the founding of the country. Difference is however it takes more skill to layout and cut rafters on site than it does to order engineered trusses from a factory. As for the insulation, contractors can only use what is available, and that has changed over time.

[@conquerordie230]

Have building codes been updated to include these kinds of attics? I would imagine that there would be a substantive amount of pushback from inspectors as soon as they don't see something they immediately recognize or are otherwise use to.

[@thomaslbane]

It’s permitted in the code. Has been for a long time.

[@MariuszChr]

Yeah, "I never seen something like that. Redo it the right way" lol

[@hailexiao2770]

It's been in the building codes for at least 25 years. No inspector is so backwards as to reject spray foamed roofs.

[@steelyspielbergo]

it's basically a story-and-a-half house.

[@drakeorion94]

That coating is amazing!

[@nholt]

So there is a vent up there with cold air coming out? And heat in the winter?

[@RDSZ]

That is a beautiful job.

[@jayworley1583]

Matt, love you videos, but for most people / builders, spray foam insulation will remain a pie in the sky scenario due to its high price. However, I do think LP Techshield + R13 or R19 in your roof rafters with a 2" air gap would be sufficient for an "upgraded" home in terms of its attic insulation, IMO. Then, get your ducts sealed /& stretched out really well over your ceiling joists with blown-in insulation over them. Finally, make sure your HVAC unit is in an insulated room / closet and add a QuietCool attic fan that operates at 70 to 110 watts to remove any excess heat. Good ventilation is also key, of course.

[@richardt6980]

ah yes closed cell foam. so when there is a roof leak you will never know it for years after the destruction is done

[@dryfly2000]

Matt touches on that in another video.

[@313theskillz]

Closed cell foam stinks to high hell

[@thomaslamb3119]

From an energy savings perspective it’s great. From a termite perspective it’s awful! Currently we have been advised not to fumigate houses that do not have ventilated attics. Additionally I’ve seen homes where termites get in between the foam and the sheeting and do tens of thousands in damage before you know.

[@TheMax13542]

energy savings on these houses isn't a real thing. If you add the attic to the conditioned space your increasing the cubic volume to cool and need to increase the size of the hvac system.

[@MariuszChr]

@@TheMax13542 it's getting balanced by overall much more superior insulation.

[@Goldarr1900]

It’s like reinventing the wheel. Some things are better left alone.

[@sunriseshell]

@@Goldarr1900 And some times NOT leaving things alone brings innovation. I don't like the "If it ain't broke don't fix it mentality". This stifles progress and innovation. With that mentality we'd still be walking and riding horses everywhere.

[@hailexiao2770]

@@TheMax13542 It is a real thing if you have HVAC equipment and ducts in the attic, which is admittedly a stupid thing to do.

[@cruzingpapa]

Instead of that mess with all that flex ducting I would have ran metal trunk lines down both sides and kept the flex to a minimum. But I installed hvac systems for 30 years so I'm a bit picky.

[@adamc457]

Yea i can appreciate this comment. good ideas to make things 100% better should be encouraged. OCD for the win

[@NoBody-ro3xj]

I would have done the same. So much better than flex

[@noelbustos764]

How much more or less does that cost, normally?

[@bradlyfkennedy]

Hello Matt! Thank you for the videos! My house was built in 1997 -- I live in Dallas -- and would like to use Rockwool in-between the attic ceiling rafters like you did in the above video. My question is, did you do a vapor barrier between the Rockwool and the inside attic roof?

[@johnlee7085]

On Matt’s house, he used zip sheathing and a double layer of insulation board and more on the outside so his vapor barrier is outside.

[@mistyjackson8766]

We have an unvented attic and it has its ups and downs. live in california and out attic never gets above 85 degrees even if its 110 outside. Now this is great during the winter cause it really insulates our house and inside will never drop below 65. However during the summer after the long hot day and when it really cools down outside it takes forever for the inside of our house to cool down even if we have a lot of windows open. Its like a greenhouse effect and the house doesnt cool down until the attic finally cools down.

[@johnlee7085]

We love our whole house fan on those hot days when it gets below 80 by 9 pm. We’re good without ac til late mornings. Maybe that’s where Matt is talking about the fresh air resupply?

[@onjofilms]

I knew someone that did a commercial install of closed cell. I asked how do you know when there is a leak? They said they had one, it built up water until it busted like a balloon onto the floor space.

[@safffff1000]

Flat roof or sloped? Failure of roofing, was the wood all rotted ?

[@drewcipher896]

Even a small leak has no chance to dry out stuck between the roofing and foam. It's just going to rot the wood between.

[@safffff1000]

@@drewcipher896 spray Jones has been doing for 30 yr successfully.

[@mistagregory]

I just want to live in Matt's perfect house.

[@GlenS123]

Dr. Joseph Lstibuerk and science disagree with you. Both done right work fine.

[@Dancing_Alone_wRentals]

Dr. Lstibuerk is too difficult to understand with his sarcasm. He is a wealth of information but locked away.

[@jimmaul]

I guess you didnt see this video where they both discussed it together? kzbin.info/www/bejne/sJnOeJahobx1lbM

[@hailexiao2770]

Lstiburek doesn't work in Texas, the land of braindead builders who put HVAC and water heaters in the attic.

[@insulwiseenergycomfortsolu3293]

Matt I appreciate your videos and think you do a nice job, but where is your air barrier in this attic? I know that rockwool can be a fine insulator, and I'm sure that in TX you don't have the same issues as we do in colder parts of the country with water vapor condensing on the undersides of roof decking (and forming mold). But in a cold snap or anytime outside temperature falls below dewpoint, my guess you will have water vapor working it's way up through that rockwool, condensing on the underside of your roof sheathing and then potentially causing some issues. As a bit of background I have fairly deep building science training and own an insulation company in Pittsburgh specializing in retrofits. Are you not concerned with having an air barrier on the upper part of your building assembly due to the climate there?

[@1SCme]

*Maybe I'm missing something,* but if you move the insulation, from your ceiling/attic floor, to your roof/attic ceiling, you just created a lot more space inside your insulated area - not a recipe to cut heating and cooling requirements. *They're noting the attic temp is close to the rest of their home,* because there's no insulation between their attic and the rest of their home.

[@dustinschmelzle7326]

your increasing the envelop but drastically cutting the conductive transfer of heat into that envelope .new building code only allow a certain cfm air exchange and spray foam actually helps out with that too spray foam generally has a beter r value so you can meet code with less of it new code require almost 2 time as much insulation as they did in the past so its easier to put some or all on the celling so you don't require 6 inch of bat insulation

[@1SCme]

@@dustinschmelzle7326 Use spray foam on your attic floor, gaining the R-value at a lower cost because you're covering a smaller area, avoiding the cost to heat and cool a larger envelope. You could encapsulate ductwork under the spray foam layer, but I would expect these would be better left above the spray foam and wrapped in insulation.

[@jimscruggs5400]

Love learning from you thank you

[@KpxUrz5745]

Would be nice to explain approximate costs of this attic construction (with that very complex air handling with vast numbers of flexible venting pipes) versus the typical loosely insulated attic. I suspect it is prohibitively expensive for most people. I also suspect that in many areas it would be difficult to find a contractor capable of this more advanced type of attic insulation.

[@Moondoggy1941]

If they do not talk about price then it is way to expensive for most people. They could easily do this in So> Cal in the fire areas, most of the fire insurance is going up 900 percent.

[@leevanbinh]

great philosophy about attic space

[@davejoseph5615]

Might be interesting to construct one long test attic with different sections using different schemes.

[@jean-loupyale2310]

Not to my knowledge.

[@davejoseph5615]

@Karl with a K I don't think so. Nothing structural is being changed.

[@davejoseph5615]

@Karl with a K All that is discussed in this video is attic venting and insulation choices.

[@davejoseph5615]

@Karl with a K This entire channel is about custom home construction.

[@davejoseph5615]

@Karl with a K Do you?

[@abialo2010]

but the moisture from below will find its way to the attic and without ventilation will grow mold

[@jimmaul]

Did you see this video? kzbin.info/www/bejne/sJnOeJahobx1lbM

[@hailexiao2770]

That's why code requires either a dehumidifier, AC supply & return, or fan & grill between the attic and the rest of the house if you have an unvented conditioned attic. It's called a conditioned attic for a reason.