As an amateur with woodworker, i typically feel overpowered with the entire arrangement ua-cam.com/users/postUgkxrYREG3-7f1Aqk9ams3ZESRNzGnfdUtyQ . Be that as it may, this arrangements drove me through with much clarity and effortlessness woodplans. Works i now work like a genius. That is great!
$250/sf is sounding cheap these days. Got quoted $265/sf last month (August 2022), so I’ve decided to GC it myself. I’m a licensed home improvement contractor working on my GC so I’m not ignorant by any means, but I’ll definitely be leaning heavily on your videos over the next year or so. Thank you for sharing your knowledge!
After reading the articles from Green Building Advisor & Energy Van Guard it looks like best practice to avoid damp roof issues in a closed attic that has open cell foam in Texas is to have both supply & return vents in the attic with a dehumidifier thrown in to complete the system. All this science is beginning to hurt my head.... Keep up the good work.
I love to see foamed attics. Your on the right track on informing others on this. As a HVAC contractor I HIGHLY appreciate this!!! However, I don't wanna see any rafters what so ever... I want to see the rafters totally encapsulated. Go look at those exposed rafters with a thermal camera on a hot summer day, to check the heat transfer through those exposed rafters.
Yes, I totally agree. I’ve gone to a much thicker install of foam (10” now) but I need to upgrade my photos. These are from a few years ago. I’m doing an insulation job next week that I’ll probably do some video on and get some good photos. Stay tuned
Great video: You not only mentioned history, but you showed pictures. You not only talked about design, but you lead the watcher through with pictures, diagrams, and examples. Thanks for the info. It gives me ideas for when I build a retirement home in Arizona some day.
Thank you, Matt Risinger. I've been planning a custom home for the previous two years. Your principles explained here has allowed me to spec certain details into my plans that I would have never had known to ask for prior. As a result, my energy calculations are a full 60% less than a typical custom home in Phoenix. I should be able to go Net-zero with PV in the future if we choose.
If you were going to do a book/ manual, I would market it to the owners, not the pro's. Educate them on what they don't even know that they don't know. They can create the demand for these techniques. Call it something like "A Homeowner's Guide to Energy Efficient Custom Homes: Principles to incorporate into your new build"
Matt, thank you for taking the time to make this video. I had watched your previous video, but disregarded it because of the lack of explanation and evidence. This gives me more leads for research and explains the logic quite well. I appreciate the followup!
Such a gorgeous book - each shed is unique and inspiring, and I love all the tiny details Kotite features to help readers imagine how to create their own She Sheds ua-cam.com/users/postUgkxe9yi0sulKgsp0VJJCIrLWWkvVqcU7LFR . The feature on Dinah's Rustic Retreat is like something from a fairy tale. It's really inspiring to see how creative all these ordinary people are in making beautiful and useful spaces on a modest scale.
At 6:24. The exhaust is ran incorrectly. The change from 2" to 3" has to be on a vertical rise, not horizontal. That's a water trap and will hold water. Bushings are a cheap way to do it. A standard reducer is called for in the venting specs.
Really enjoy your no-nonsense approach. I always learn something new from your video's, and I like that you methodically take the time to do things the right way.
Here in the Northeast, you'd have serious problems with your lender at $250/gsf.. The local small custom builders are ballpark $125--150...excluding land, fees and the Architect. And the large production builders are $110--125/gsf ...including the Architect. This is unless you are building a "trophy home" well in-excess of the local real estate market...and self-financing. Gone are the days of mortgages in excess of estimated appraisel.
I always enjoy your videos. I'm a TREC Home Inspector in Corpus Christi and it just blows my mind that builders moved the HVAC from a closet in a conditioned space to inside an unconditioned attic. All of my ductwork is in furdowns in my duplex (I have a flat roof that I absolutely hate, but that's another topic). I've been taking notes on your builds to apply what I can to my low income housing construction jobs. So far I'm going to go with roof trusses and open web trusses for the second floor, use Proseco liquid applied vapor barrier, open cell in the attic space. We're doing mini split ductless and a few other things.
I absolutely *_love_* that last house! And why are people criticizing you for building expensive houses? You get what you pay for. Either pay the premium now and get quality that will last, or go cheap now and end up paying the premium anyway, later on down the line, when everything starts rotting, molding, or just falling apart in general.
Its also the prices, my 300K ( just bought ) house in the 80s cost a ton less to build, if I were to try and build it today the way it sits It would be probably around 1.2 mil. The prices and labor have went up so buying a house is a lot cheaper than building around my area anyways.
Umm I swear ! I’m umm , I hearing this right, no ventilation to roof!!! Ummm well first I am curious as most people put roof vents but forget soffit vents to circulate the air, keeping continuous air flow and no moisture problems and no heat problems as I would like to see the life of those shingles as asphalt singles life can be cut down drastically by overheating, ask any roofer what curled shingles mean, over heated... moving air through the attic is to keep it within 10degree of outside air... I’m wondering if he doesn’t fully understand how a vented roof works and it’s purpose... I am not doubting anything about him straying foam into trusses as I have not done any testing but I would guess keeping the heat pushed up against the singles cut la the life just like a poorly built and designed circulation (vented attic) as it’s not just roof vents, it a whole system of flowing air, cool air comes in soffits and hot air flows out roof vents, cooling your singles and adding life (maintaining the existing warranty on life of shingles) Now I have worked for 30 years redesigning roof (attic) ventilation system as yes in 70 and back there is lots of design flaws.... You should never keep heat up against the roof shingles because a roof cost lest say $10,000 and should last 30 years... now to much heat will cut the life down to as little as 10 years costing you lots of money as a $10,000 roof the way he is saying could have to be replaced 3x now costing $10,000plus as you have to tear it off twice.... Ughhhhh it’s scary when people don’t research stuff and understand the true intentions of a vented (circulation of an attic) I really hope he gets engineer to explain things to him he is saying is old or out dated... yes just roof vents is a problem but that’s why you install soffit vents and move air through the attic, removing hot air and cooling the space... adding life to your shingles and saving tens of thousands of dollars... I did see he showed a metal roof and venting inbetween metal and roof, yes that can be done and if that’s what he’s doing than ok that’s done right, but the soul purpose of a vented roof is to circulation cool air in soffit and hot air out top of roof, if done 100% right with proper vents at both ends, the roof (atttic) is within 10 degrees of out side air not 130-140 degrees ....70 degrees out side (roof/attic space is between 60-80 degrees and if all flows right no moisture problems at all. I have worked on installing proper ventilation on roofs for 30 years and yes some of the stuff he has said is improvements, but also some of the stuff is going to cost people ten of thousands if some of the problems he’s causing are not properly dealt with... I hope everyone the best of luck as it sucks when someone gives out bad information or does not understand a situation or system.. I have had to teach many contractors, roofers, siding guys, insulation guys the importance and why it’s called a system, it’s been a huge problem when people get the wrong information or when a builder don’t understand the purpose of something... Now if he understands venting a metal roof, why is he not venting asphalt and other roofs and trapping air up against shorting the life of the singles.. so hopefully this reaches him and he further studies and understand why there is a ventilation system for a roof, attics and it serves a huge purpose to add life (or not let heat shorten the life) Hint if your singles are curled up it’s the most severe case of too much heat, there are many other signs but that’s the most noticeable... Huh well at least this won’t be such a huge problem in the future as people get to point out people when they obviously have no understanding or confused (he sounds confused, venting metal roof but not others) Any further information feel free to contact me as I have dealt with this so many times and have had to help fix so many new built homes as some contractors thinks he has a new way and you need to fully understand the old way before you improve on it.. Yes you can spray foam trusses but you still need ventilation (well it saves tens of thousands over the life of your roof, among other costs) not sure what education he has or what degrees he has in engineering but if you speak to any engineer that knows how, why houses where design a certain way, than you would understand.. Oh I will also ad, a lot of times in construction under trained workers that don’t know why something is done will sometimes not do it right... especially when a siding guy, don’t know his soffit vents are of importance or insulation guy covering up vents or roofing guy not putting in proper amount of vents to create the flow based on square ft, volume of attic, so on and son on... Well hopefully people will look into the right way and understand you can improve but first understand how to do it right, don’t base improvements on something done wrong as I have heard all his reason of being better as being based on the wrong way to vent (circulate air in a attic) so hopefully he can learn the right way to vent an attic and than improve... Just hope his customers are not having issues as he is long gone as the problem come up about 8-10 years after in southern states and in cold climates the first winter can cause major problems with ice dams, water leaks so on... it’s better to think smarter work less.... education is very important and sad in construction as most contractors have no schooling only on job training and if it was taut wrong or not taut at all than you will Get this video and lots of guys saying stuff that sounds good but is deceptive and costly to homeowners
Expensive houses are great. Most of Matt’s videos have great advice and are very educational. It is just that as a professional I found this particular video to be well intended, but of poor advice. Radiant heat (long waves) goes through spray foam and blown insulation quite easily. Having airflow next to a radiant flow barrier that is under the roof decking will block most of the radiant heat waves from entering the attic and keep the attic temperature within 8-10 degrees of the outside ambient air temperature and help reduce the heat load to the roof decking which is better for asphalt shingles. I have see too many roofs where the asphalt shingles were destroyed from the thermal mass buildup due to lack of ventilation below the deck and moisture that got trapped underneath. Moisture destroys everything. That being said, now you can go about sealing, insulating and conditioning the attic space where you don’t spend a lot of your time. Just don’t short circuit the airflow under the roof deck. Kudos to Matt for all his fun and educational videos.
HickoryDickory86 Bullshit. 250/ft^2 is about 2.5 times the avg here in N. TX. My home would cost me 912k to build with those figures!!! do you know approx how long it would take to recoup the 5-550k delta??? please......
Thanks a lot for putting out this video. i just recently bough a 1951 house in the Brenham Texas area, and my attic looks like the house at the start of the video. Your videos helps a lot as a research and plan on how I want to bring my lovely old house into a modern century.
it is funny watching these past few videos, I have always wanted to buy an older home (CHEAP) gut it and make it extremely energy efficient and all that you talk about are the things I wanted to do to it.
Me too, because I love the older big trees, and then I see the crappy layout, cut up floor plans, small closets, low ceilings, and shitty mechanicals, and then I decide to build another brand new house😀
It's hard to retrofit a old house and get anywhere the insulation efficiency and benefits of the newer ones, specially if it was built with 2x4 walls and 24" centers, narrow, tall windows,small rooms with up to 4 doors per room, small or no closets and no bathroom to begin with and very crappy foundations with plumbing added much later along with the electricity in the 50's and is over 100 years old and had coal stoves in 1912 to start with. I would have been better off in a double wide.
“Do the right thing” should be the operating rule for every builder. Unfortunately it is not always the case when expensive mistakes are made in choice of materials or construction techniques. But, when the wrong thing gets done, “Do the right thing” means fix it at your expense, not the customer. You passed the test of a builder with integrity. If I were building in your area, I would try to contract with you. Well done, sir.
Roofs should be vented underneath THEN insulation to isolate the space. Mike Holmes covered this. The top and bottom surfaces of a roof should have equal temperature (or close to it). Moisture is reduced and can evaporate. Snow cover will not ice-up... PLENTY of advantages. Space lost is inches, you just want a channel between rafters, outside the house envelope from wall to roof peak.
Matt, I have a 17 year old house that has conventional blanket insulation on the floor of the attic. When I bought the house 2 1/2 years ago, I was going to add insulation but ran out of budget after re-doing the inside. Now I don't think I will do anything. Whoever built this house insulated the basement in an unusual way. Curtain drains around the foundation leading to one of three sump pumps that never run - one is a grinder pump so I can put a bath down there, one is a sump pump required by Ohio law and the third is a water powered back up pump if we need it and have no power. Then on the outside (poured concrete foundation with brick pattern in and outside) he sprayed the foundation with an asphalt product, applied a mesh product, sprayed again and then use 4" of rigid foam to the dirt line. On the inside I used two coats of Ultra Drylok followed by two coats of SW brilliant white paint and two coats of SW concrete on the floor. No dehumidifier needed, constant 68 degrees year round. Replaced the furnace and A/C system courtesy of my home insurance with a high efficiency system. No round ducts, all rectangular old style but easy to clean. 2,800 useable square feet with utilities
I sprayed closed cell right to the bottom of my roof deck in Canada. 1890's home. Allowed me to get rid of the attic all together and open up the ceiling, add skylights. It's been an absolute dream.
Florida is starting to ban or extremely limit any spray foam. You can not spray directly on any exterior wood structure, from the inside. They are finding that when a leak does occur, the water runs into the nail or exterior fasteners and fills the foam with water in those spots. And this develops Black mold. Also, some insurance companies are not insuring homes that have spay insulation on the under side of the roof, if they had a new roof put on after the insulation was sprayed. Because of all the nail penetrations in the foam.
I am enjoying your videos very much. I will be building a barndominium near Taylor this year, and you are giving me good ideas on how to make my house very air tight and energy efficient. I also am going with the little mini air/heat units instead of central AC to cut down on cost. I also thing after the place is done, I won't need much heating and cooling in order to maintain a constant temp.
My place is about 12 years old. We just moved in about a year ago. We are in the Waco, TX area. I have a very voluminous attic and the builder used "fluffy stuff". We just replaced all 15 windows with a very good product that uses argon exclusively in the double pane windows. The window areas are very tight now and I can tell already my cooling bill with me significantly lower this summer than last. The home is a single story 1650sqft home. Mostly brick and some Hardy Board. I'd love to go to foam and "conditioned" attic design AND convert that huge attic space into some living space. I don't want to overbuild for my neighborhood from a value perspective, but we're going to be here for a while and would like to add value and equity with such a conversion. What would you guess might the cost of doing that type of conversion? I might be able to get as much as 400sqft of living floorspace out of our attic. I'm just trying to conclude if it's worth it.
Thanks Matt for everything you do. I've watched you for years now, and every little repair or upgrade I do is based off of your expertise and recommendations. Keep up the awesome job! My question is would you recommend converting a "production" home in San Antonio with a vented attic, into an exterior insulted home? Or just stick with converting the vented attic into a condition sealed space? Home was built in 2008 and is coming due for a paint job, and most days I'm a few minutes away from ripping all of the Hardie board off the exterior, so I can beef up the air sealing and insulation. Should I invest in this current home, or invest in a new home? The house is two stories, slab-on-grade, with radiant barrier/foil board roof with asphalt shingles.
Yikes who would thumbs down this video?? Anyway great info!! I am going to see if spray foam insulation is feasible for my attic. I am wondering though if when I re roof my house whether it would make sense to put the insulation on the exterior and then re roof.
Don’t be bothered by the thumbs down. Almost any video I Post gets 10% thumbs down and 10% of the comments are how I’m “an idiot”. If you’re going to reroof the house, consider and Insulation upgrade on top of your roof, then a layer of nail base and your new roof. No spray foam necessary. The only thing you’ll have to do is seal off your vents and in sure there’s no outside air leaking into your attic. Thanks for commenting! ( and the 👍🏻)
Matt Risinger its prob mostly contractors that thumbs down. He is a very whiny person who complains for no reason. The first attic he showed obviously had some work done after build and they never put back the insulation in that spot. He likes to spend a lot of money that the average person cant afford. I would really love to see him build a budget house.
Really liked the plenum space in the trusses. I’ve designed trusses for 30 years and have not seen this detail before. I’ve learned a lot on this channel. One of my favorite! Keep em coming.
I've slowly come to the conclusion that floor plans should have machinery space and narrow halls to house HVAC duct/plumbing/electrical built into the inhabited levels. Adding 400 sqft into the average home is pretty cheap up front and will pay off massively over the life of the home between energy savings and much easier maintenance.
Those ideas certainly cost less and conserve floor space, and are a big improvement over what is done now, but I just like the idea of being able to easily inspect and work on the vitals, also easy access for potential upgrades or future changes. I guess I've seen too many instances of rodents, who can amazingly manage to appear and be in places never thought possible, chew up insulation and flexible duct work. Having all that duct work effectively sealed from view could well mean chewed up ducting with 5 pounds of rat turds inside it. Maybe these newest very tight and sealed homes are completely rodent proof, but I have a hard time believing that. Also having as much of the plumbing and wiring in an easily inspected area adds to the over all safety factor, but where I'm at, square footage gets pretty cheap once you pass a certain point, and the land to build on is cheap as $5k an acre would be a high price a few miles out side of town. In more expensive markets, it would be a much more costly proposition to surrender so much floor space to machinery.
As an engineer and builder in the northeast, I have always tried to have the air handler and distribution in the conditioned space. This is an energy efficient approach that is easy on the equipment.
Is there any thought on what happens if/when the roof fails and sheathing starts to get wet? Will the spray foam need to be cut out and replaced? Also $250 per SF is very expensive in my neck of the woods. I can build a 2,000sf ranch style home that meets all of California’s building and energy calcs for about $125 a foot. Your permits, and labor rates must be through the roof.
I’m guessing he can build it for a lot less than 250 a foot, but I doubt he wants to advertise that fact to his clients. Which are probably willing to pay in that range. Not that unusual in my neck of Texas for a nicely build home on some property.
As a claims adjuster/ inspector here in Louisiana. I’ve done many roof and attic inspections after storms. The attics with spray foam are the worst and hardest to find where the water entered because it runs underneath the foam and drips in a completely different area. Al’s to replace the damaged you have to rip off the entire area decking. Many times people discover rotted sheathing and rafters which mean it did start from the storm. The storm just revealed it. Many insurance companies are starting to not cover this stuff and exclude it.
I have open-cell foam under my roof sheathing of a 1945 walk-up attic in Massachusetts. Seven years ago the closed-cell was double the price but was informed that if/when the roof ever leaked (using closed-cell) I wouldn't know until the walls showed signs of moisture. With the open cell the leak would pass through the foam and show on the attic floor or spot on the ceiling downstairs. I know many houses don't have floored attics throughout the country but it was one of the reasons I bought it.
Great video, glad to see you adopting attic conditioning. I have been espousing the benefits of attic conditioning to contractors that I speak to and they look at me like I'm speaking a foreign language. I have a question for you, In the attic, can you attach radiant foil to the bottom of the roof before you spray on the foam? I would think this would help a conditioned attic even more by radiating a lot of heat back out toward the sun before it has a chance to make it past the spray foam insulation.
Unvented attic will make comp shingles deteriorate much more quickly, also makes leak detection and diagnosis/repair much more difficult. Something to consider! IMHO It's a trade-off Mr. Risinger
Informative video like always Matt thanks for sharing. I hear people say that "Quality Costs" and may be true but peace of mind and time are priceless.
We have a 1970 ranch house with a low pitch roof (50x100) with vents/ridge cap/sofet vents. each year we would get 140F in the attic and the AC was on 22 hours per day. About 4 months ago we had open Cell foam sprayed into the rafters (roof decking?) and its about 6-7 inches think. we completly sealed the attic and OMG what a difference. the AC is only for a few hours per day and the noise and dust is way down. also we don't get condensation dripping from the vents! so all I can say is worth the $7K we paid.
I'd also like to know if your roof shingles would be adversely effected by spray foaming your roof sheathing. Wouldn't the shingles tend to get a lot hotter in the summer and cause them to curl? A question for a roofing contractor or a shingle manufacturer perhaps.
You're absolutely correct it should be done with baffles between the rafters so you have a small air space between the roof decking and the insulation or put a water screening material on top of the rafters before the roof decking goes on
I love this channel and watch every video. This one brings up a few questions though. Wouldn't spray foam insulation in the rafter bays prevent roof leaks from entering the house and cause a roof leak to go unnoticed until the roof partially caved in from dryrot? Don't you want roof leaks to drip on the ceiling drywall and make water stains to warn of a roof leak so it can be fixed before causing structural damage to the roof sheathing and framing?
Not to mention that you cant recycle wood that has spray foam on it. And imagine that a house full of spray foam catches on fire. There would be a huge column of black smoke billowing off.
A good question, but consider the average homeowner who doesn’t go into their attic space regularly. I recently noticed a roof leak near my plumbing vent pipes, but the decking has already begun to rot. Why didn’t I notice ceiling stains? Because of the partial flooring, and items I had stored up there. Lessons learned, I suppose. In a conditioned attic space, though, it sounds like a hygrometer would be a good idea to detect roof leaks, since it’s open-cell foam. What do you think?
As an insulation contractor and fellow building science geek, I love to see conditioned attics becoming more accepted. I still have a lot of folks resistant to the thought especially with the costs being higher. I am always proud to see a completes conditioned attic and knowing that it will be so much more comfortable than it was previously. One thing that is making things difficult in our city is the requirement for a Thermal barrier over the foam if there are mechanical systems in the attic. Are you dealing with Ignition and Thermal barrier requirements in the south?
Yes, we have to do those as well. I’m not super happy about them, but I do understand the need and the code requirement. My preference is to use a foam that does not require it
$250.00 sqf is very north of most custom home budgets. I really like your videos but that statement sounded more in line with a money's not a concern build!
I would expect a lower cost in other parts of the US. But we need to set higher expectations for performance on our homes. Gone are the days of a home built for $xxx/ft (Insert local average cost). A well-built home with good systems, a thoughtful design, and good tradesmen should cost 1.5x (local average cost). We should be building homes that last a few generations without problems, that are healthy, durable, efficient and long lasting. Build better not bigger.
Matt Risinger, that's great if you can recover the premium cost within a 5-7 yr window but the resale price of the home will only bring $ average of "like" homes recently sold. Unless the owner can document real utility saving to project forward the home will likely not resell for a premium.
Michael Amick yep, have seen this happen to many people that custom built there home. Then bank comes in and says I don't care about your upgrades or how well you insulted, a house in this area is worth x per sq ft and that is all we will grant a loan for. It's a sick feeling to spend $250k on a house where you did a major part of the labor yourself because it was your profession and the bank says it only appraises for $180k.
Hard to say "most" when referencing anything. Our client base covers homes primarily $1.2 -$15 M and we are just south of Austin. Everything is relative .
at 7:12, where is the tie-down straps holding the roof trusses to the headers/2x4's? or is this built AWAY from coast line? Very far away from a coastline?
A ton of comments, nice job Matt. What do you think of this detail from interior to exterior: Closed cell spray foam < roof sheathing < two layers of 2in XPS foam boards w/ staggered seams and tapped on exterior layer < Furring strips < zip system roof deck < two layers felt paper or smart membrane < shingles.
Matt, I rarely agree with you as much as I did on this video. I loved the concept on your "monopoly house". I totally agree with conditioned attic space with radiant barrier and a breathing roofing system. I probably would have kept the house a bit lower to the ground and had covered patio, porch where the large windows were to cut down on direct light even though it was a wooded lot. loved the open floor design. People sometimes don't understand cost and quality along with speed of build. you will always pay good money for a real craftsman and more if you want it fast. A well built home like that 1 keep the buyer happy for a very long time only needing to change out the water heater in 12 to 15 years and maybe a paint job. Maybe hire out a reputable handy man to clean the gutters and check your caulking every year. It will hold value and peace of mind is priceless.
Hey Matt great video. I’ve been a long time fan. Big question though if you’re using a spray foam on to the decking of the roof how do you handle venting for the roof?
I prefer a baffle between the roof decking and insulation this allows air flow from the soffit to the ridge line to keep any moisture water vapor and condensation to vent and dry out it also prevents mold mildew and it keeps the decking the same temperature on both sides to prevent these problems great question ⁉️
how long do the shingles last . We know that lack of ventilation will shorten the life of shingles in a 70's type attic. How do you detect a leak in the roof? The ceiling foam looks like it could create other problems.
I'm in florida, and I had always heard insulating between the roof rafters, under the roof decking, increases the speed of deteriorization of roof shingles, because there is no ventilation under the shingles to help carry away the heat. Is this not true in your understanding?
Fire codes?? That much closed cell foam needs to be covered for fire codes in our area. Plus it would cost $20,000 to $30,000 the house will never make up that cost.
@Ego Twistick Not all of us live in California and Texas! Where I live, two story plus a basement is a very common building plan. I grew up in such a house, and I would probably build that way if I were building a new house.
I replaced the Bat insulation in my attic with R60 closed cell spray foam back in august and got new 95% efficiency furnace. This year was the coldest year we've seen in 40+ years in Alberta and my bills were half of what they were last year during a very warm year. In fact the last month we've been around -10C to -15C at night and my records show the furnace didn't kick in till 3am. It is so worth it.
Matt what is the process when you have to replace a sheet of decking and the underside has spray foam. Does that foam have to be cut out and reapplied?
Yes, pretty much anything with spray foam has to be demo'd. Seen entire reroofs chainsawed off because the sprayfoam formulation wasn't correct and the house was a toxic hazard and nobody was able to live inside.
I like the suggestions Matt Risinger has made. It seems to me, logical to put the insulation barriers of a building as near to the outermost "skin" of the building as practically and permissibly possible (ie in compliance with relevant codes). Placement of any of the machinery, used to condition the living space, within or outside that conditioned space, should be such as to provide the most positive effect on the living space, while allowing the most efficient operation of the machinery. The placement of the machinery would provide the best possible facility for its maintenance and future possible upgrade, whether in a specifically created ceiling/roof plenum space, a basement, an attic, adjunct to a utility room, outside utility room or even a separate building space away from the main building, which would allow for isolation of noise and vibration. Protection and maintenance of the surface material or skin (cladding) of the building should, I think, be dealt with separately and independently from the insulation of, and maintenance of the living space environment. Cladding protection should be dealt with by the choice of underlayment; vapour barrier choice; facilitation or blocking of air movement & direction by ducting and venting; decking choice etc.. The reverse effect that the cladding has on the conditioned or passive environment of the living space is, to my way of thinking, the only consideration connecting the two. Books, training videos and youtube videos improve the information base of all people involved in building. This means owner/clients are better able to discuss various methods, options & costs with their builders, from a much more informed and improved knowledge base; DIYers have better information for their projects; and builders can expand the options for their clients with a sound and qualified knowledge base to support their suggestions. Obviously, all chosen options are required to meet code standards, and sometimes that may be easier with expanded options, and provide improved outcomes in terms of quality of living space. All final options must be based on sound and qualified information, and be practical for the application. However, "white-boarding" of ideas, whether the application of the ideas are cost efficient, practical or even "sensible", or not, can be the conduit through which best outcomes can be finally arrived at. Cheers, Peter
Ah, you must understand this is Austin, TX, where Matt lives and works. Average home price is now north of $400k. My 1982 vintage ranch is appraised at $180/sq ft.
It's all about where you live. I worked in the San Francisco Bay Area 20 years ago and $250 sq.ft. was bottom of the rung home construction cost. I can't imagine what costs must be like there now.
Matt Risinger I really do enjoy your vids. It's amazing what people in Austin will pay for a house, lol. Exposed rafters for $250/sf, not my thing. Now, zoned cooling, mini split heat pumps, yes. All those flex duct runs in unconditioned attics in Texas, throwing money away! The most cost effective retrofit for almost every existing ranch style house (and others obviously) in Texas other than large deciduous shade trees west of the structure is an adequately sized attic exhaust fan. There's better cheaper ways to build, why not??? I'm all about sustainable design. I'm hoping to really start seeing examples from you. It's our future. If you want to build hugely profitable affordable sustainable (non combustible) homes look me up. It amazes me nobody sees it. Plus as everyone transitions to driving EV's, (whether you're aware of it or not) installing rooftop PV solar in Austin and places south and west all the way to the Pacific should be a no brainer. Keep up your great work! You are a great resource. Thanks
^^^ That is the million dollar question !!! If it doesn't translate into substantial savings, then these videos are much ado about nothing. And when there are no efficiency numbers to accompany the videos, that's fishy.
No offense intended but when you spray open cell foam insulation it should be sprayed evenly and not exceed past the trusses. You should see the boards after expansion. You end up with a r value of 32. The foam should be relatively flat. That's how we do it up north. Love your show man keep them coming. I'm a builder who appreciates outside advice or better ways for building
Spray foam can be the Devil's work, specially considering the adventurers in the business. Mixing chemicals like that, when improperly sprayed, can cause health issues in future residents. But getting insulation under the roof is a must! I really appreciated that wrapped house with "external" insulation as a reasonable and practical solution.
Yes spray foam sucks over the long term. Asphalt shingles have little or no warranty when installed over a spray foamed deck. In hot humid climates it will cause the decking and shingles to buckle. Spray foam is the best worse thing you can do to your home. Run from any home that has it especially in a high humidity location. Additional mechanical systems are required to remove moisture from the attic space these systems will add $10,000 to the cost of the home and require regular maintenance and have a expected life span of 10 years. At which time you will spend another $ 10,000. The best bang for your buck is R-38 insulation and a well ventilated attic. I only have experience in Florida with the spray foam. This stuff is a maintenance nightmare will be compromised at the first roof leak that needs to be found. Your roof will probably have a shorter life cycle due to the heat building up in the decking and roofing product instead of dissipating into the attic space and then vented out. DO NOT USE THIS PRODUCT ON YOUR HOME THE ONLY POSITIVE IS A COOL ATTIC EVERYTHING ELSE IS A NEGATIVE. So for 1/20 the cost of foam go with R-38 batts or blown insulation and use the savings for a pool, man cave vacation all led lighting outdoor kitchen,solar panels etc etc the solar will pay you back for years to come. The foam will cost you for years to come. This is my opinion only from over 40 year in the HVAC trade. Google spray foam and roof warranty. This alone will cause you to run from this stuff
Open cell foam doesn’t hold water ...water will come through it and you’ll see where it is coming from. Open foam is easily removed so you can repair that area. Closed cell foam is NOT to be used in the attic because it will not let the water through which will cause rot in time.
Some of my family still lives in Poland. Most homes have stucco on the outside, about 20 years ago, one of my cousins was insulating his home from the outside like you have shown on the last home. They used large sheets of 2” foam board and attached it to the outside of the home. What are they doing today, who knows, haven’t been there since 2005. The home I’m talking about is in Rzeszow, Poland. Most homes are built from blocks (concrete, clay, etc.) and heating systems are hot water. Most homes have no insulation, unless they are built within the last 10-15 years. Many homes are self contracted, and usually are representative of where the person lived outside of Poland. Comments?
Great video, but don't forget to warn people that spraying attic foam can be "toxic" and end up contaminating the whole house and eventually have to remove the whole roof!
Cool deal! I love the last house that you showed. My whole life I have been wondering why we always had to put insulation on the inside of buildings. It never made any sense to me. Thanks for showing that you really can insulate out side of the box. :-D
4:21 you talked about doing it, but it wasn't done, so really you've created a conditioned space which is not ventilated. A closed sealed area, with no ventilation. Professionals like to call that a man trap, where people go to die from asphyxiation. Good rebuttal.
I did a conditioned attic in Phoenix Arizona 10 years ago and they thought i was nuts! It was convincing the building department to let me do it was the biggest challenge.
Do your retrofit when you are about to replace your roof and maybe go with a standing seam metal roof like matt did on that monopoly house. Your walls? are you brick? Just sticking my nose in your business.
I’m up,here in northern Illinois preparing to build a new home. My concern is roof deck temperature with this system since ventilation has been eliminated. Thanks, great channel
Hey Matt! Great video as usual. Always entertained by negative posters and people who do like the videos... wondering if you might do a video on strength of using foam and also a video for us down here in the south of strengthening the building for hurricane resistance?!
Here in Ga too. You could probably cut cost with 2 x 6 exterior framing and using that 3" of insulation board he used but the wood will telegraph some outside temp to the inside. The roofing system was spot on.
I payed 150k for my 2080sqft house.....yes i have the fluffy stuff....that means i payed 72.11/sqft......with his math id pay 250/sqft.... Or 520k for the same size house....a 370k difference....over 30 years id need to save 12,333/year in energy savings(this doesn't even include the financing of that extra 370k over 30 years)
I like the long form. You should build up north in the summer so you can teach Northern folk how to build. We have a lot of problems with all the snow and temperature differences we get. Plus basements!
Great video. I really enjoyed the discussion. Maybe you could make a video and talk specifically about how you would take one of those “dumb” houses and convert it into a smarter, more efficient house. What are the systems and ways to correct the problems and are there things that just can’t be fixed. Thanks
I'd like to share my experience with high efficiency furnaces in unconditioned spaces and the lack of local codes and knowledge. It's almost comical but these poor home owners are the ones having to pay for mistakes made during the new construction process.
You're right they pay the cost of contractors short cuts poor engineering and poor quality in craftsmanship it's all about as cheap and quick as possible for as much profit as possible they don't care about their customers even after the sell in resolving problems it's a cheap bandaid fix maximize profits is all they are concerned about
It is nice mounting the utilities up in the attic! But by insulating the underside of the roof, you will cook the shingles - best to use light colored shingles in that case. Alternatively, keep one inch of air space between the insulation and bottom of the roof with vents at the bottom and top of each channel between the rafters to allow for venting of that small air space. You can make that one inch of airspace using XPS (a lot of work) and then add more insulation below that to get the R value up.
Matt Risinger I think it might, though I'm certainly no expert in the construction field. But I think that even if just DIY-ers pick them up, there is bound to be some market for such videos. That said, I would hope that the more respectable contractors would pick them up as well, and maybe use them to train their new recruits (or even the old hats for particular, challenging jobs).
Matt, how about putting in a few numbers so they know the why? Even then, still an uphill push (currently having difficulty enacting ECMs that I have shown to be very effective using eQUEST). I would watch, never know what you missed and could learn.
You have had much time using spray foam? I have found on paper it looks good. Any leak will go unnoticed until it is too late an by to late mold growth so damaging beyond repair the whole house has to be demolished.
I wish you went into more detail about pros cons of roof leak issues with open vs closed spray foam. Also, is 90% efficient ac that important when you put money into a vent free attic? More detail on the ac noise dampening would have been interesting as well. Lastly, what type of foam does not need a thermal barrier? Thanks for your videos!
No it's not ok, 1) voids shingle warranties, 2) tends to trap moisture or condensation against wood, problems 5 years down the road. We are just beginning to see issues with spray against roof decks sprayed 5-7 years ago.
I do not agree with Matt on this spray on insulation direct to the sheathing. The APA (American Plywood Association) specs out requiring that one side of the OSB or plywood have an air space next to it to allow moisture to escape away from the wood. Radiant sheathing will also require that there be an air space next to the foil laminated side. I would recommend a ventilated radiant barrier roof deck using a double deck with furring strips or installing a full coverage baffled underside to a continuous vented soffit and up to ridge vents to achieve a 1/150 nfa. Then a foamed underside could be achieved. The direct foamed decks are a nightmare for finding leak issues and if the decks have to replaced, oh boy. I believe that GAF has a really great vented roof decking product that would offer the best of all worlds.
I'm not a fan of spray foam as the primary insulator, but IMO it can play an important role for air sealing. That was a very cute house though, Matt. I love the exposed look, which is much more interesting and beautiful than drywall.
what about the health issues from isocyanate..the spray foam..aka polyuethathane..not saying it not great for insulating..but that is only part of the story..
As an amateur with woodworker, i typically feel overpowered with the entire arrangement ua-cam.com/users/postUgkxrYREG3-7f1Aqk9ams3ZESRNzGnfdUtyQ . Be that as it may, this arrangements drove me through with much clarity and effortlessness woodplans. Works i now work like a genius. That is great!
$250/sf is sounding cheap these days. Got quoted $265/sf last month (August 2022), so I’ve decided to GC it myself. I’m a licensed home improvement contractor working on my GC so I’m not ignorant by any means, but I’ll definitely be leaning heavily on your videos over the next year or so. Thank you for sharing your knowledge!
How did it go?
After reading the articles from Green Building Advisor & Energy Van Guard it looks like best practice to avoid damp roof issues in a closed attic that has open cell foam in Texas is to have both supply & return vents in the attic with a dehumidifier thrown in to complete the system. All this science is beginning to hurt my head.... Keep up the good work.
I love to see foamed attics. Your on the right track on informing others on this. As a HVAC contractor I HIGHLY appreciate this!!! However, I don't wanna see any rafters what so ever... I want to see the rafters totally encapsulated. Go look at those exposed rafters with a thermal camera on a hot summer day, to check the heat transfer through those exposed rafters.
Yes, I totally agree. I’ve gone to a much thicker install of foam (10” now) but I need to upgrade my photos. These are from a few years ago. I’m doing an insulation job next week that I’ll probably do some video on and get some good photos. Stay tuned
Great video: You not only mentioned history, but you showed pictures. You not only talked about design, but you lead the watcher through with pictures, diagrams, and examples. Thanks for the info. It gives me ideas for when I build a retirement home in Arizona some day.
This is a really really cool house. I love all the exposed interior studs and beams.
Thank you, Matt Risinger. I've been planning a custom home for the previous two years. Your principles explained here has allowed me to spec certain details into my plans that I would have never had known to ask for prior. As a result, my energy calculations are a full 60% less than a typical custom home in Phoenix. I should be able to go Net-zero with PV in the future if we choose.
If you were going to do a book/ manual, I would market it to the owners, not the pro's. Educate them on what they don't even know that they don't know. They can create the demand for these techniques. Call it something like "A Homeowner's Guide to Energy Efficient Custom Homes: Principles to incorporate into your new build"
So nice to see attics that have usable space! The home I grew up in had a walk in attic and was great for extra storage. Love the look of the house!
Matt, thank you for taking the time to make this video. I had watched your previous video, but disregarded it because of the lack of explanation and evidence. This gives me more leads for research and explains the logic quite well. I appreciate the followup!
Such a gorgeous book - each shed is unique and inspiring, and I love all the tiny details Kotite features to help readers imagine how to create their own She Sheds ua-cam.com/users/postUgkxe9yi0sulKgsp0VJJCIrLWWkvVqcU7LFR . The feature on Dinah's Rustic Retreat is like something from a fairy tale. It's really inspiring to see how creative all these ordinary people are in making beautiful and useful spaces on a modest scale.
At 6:24. The exhaust is ran incorrectly. The change from 2" to 3" has to be on a vertical rise, not horizontal. That's a water trap and will hold water. Bushings are a cheap way to do it. A standard reducer is called for in the venting specs.
Good eye.
Really enjoy your no-nonsense approach. I always learn something new from your video's, and I like that you methodically take the time to do things the right way.
Here in the Northeast, you'd have serious problems with your lender at $250/gsf.. The local small custom builders are ballpark $125--150...excluding land, fees and the Architect. And the large production builders are $110--125/gsf ...including the Architect.
This is unless you are building a "trophy home" well in-excess of the local real estate market...and self-financing. Gone are the days of mortgages in excess of estimated appraisel.
I have to hire you for 125- 150
I always enjoy your videos. I'm a TREC Home Inspector in Corpus Christi and it just blows my mind that builders moved the HVAC from a closet in a conditioned space to inside an unconditioned attic. All of my ductwork is in furdowns in my duplex (I have a flat roof that I absolutely hate, but that's another topic). I've been taking notes on your builds to apply what I can to my low income housing construction jobs. So far I'm going to go with roof trusses and open web trusses for the second floor, use Proseco liquid applied vapor barrier, open cell in the attic space. We're doing mini split ductless and a few other things.
I absolutely *_love_* that last house!
And why are people criticizing you for building expensive houses? You get what you pay for. Either pay the premium now and get quality that will last, or go cheap now and end up paying the premium anyway, later on down the line, when everything starts rotting, molding, or just falling apart in general.
Its also the prices, my 300K ( just bought ) house in the 80s cost a ton less to build, if I were to try and build it today the way it sits It would be probably around 1.2 mil. The prices and labor have went up so buying a house is a lot cheaper than building around my area anyways.
Umm I swear ! I’m umm , I hearing this right, no ventilation to roof!!! Ummm well first I am curious as most people put roof vents but forget soffit vents to circulate the air, keeping continuous air flow and no moisture problems and no heat problems as I would like to see the life of those shingles as asphalt singles life can be cut down drastically by overheating, ask any roofer what curled shingles mean, over heated... moving air through the attic is to keep it within 10degree of outside air...
I’m wondering if he doesn’t fully understand how a vented roof works and it’s purpose... I am not doubting anything about him straying foam into trusses as I have not done any testing but I would guess keeping the heat pushed up against the singles cut la the life just like a poorly built and designed circulation (vented attic) as it’s not just roof vents, it a whole system of flowing air, cool air comes in soffits and hot air flows out roof vents, cooling your singles and adding life (maintaining the existing warranty on life of shingles)
Now I have worked for 30 years redesigning roof (attic) ventilation system as yes in 70 and back there is lots of design flaws....
You should never keep heat up against the roof shingles because a roof cost lest say $10,000 and should last 30 years... now to much heat will cut the life down to as little as 10 years costing you lots of money as a $10,000 roof the way he is saying could have to be replaced 3x now costing $10,000plus as you have to tear it off twice....
Ughhhhh it’s scary when people don’t research stuff and understand the true intentions of a vented (circulation of an attic)
I really hope he gets engineer to explain things to him he is saying is old or out dated... yes just roof vents is a problem but that’s why you install soffit vents and move air through the attic, removing hot air and cooling the space... adding life to your shingles and saving tens of thousands of dollars...
I did see he showed a metal roof and venting inbetween metal and roof, yes that can be done and if that’s what he’s doing than ok that’s done right, but the soul purpose of a vented roof is to circulation cool air in soffit and hot air out top of roof, if done 100% right with proper vents at both ends, the roof (atttic) is within 10 degrees of out side air not 130-140 degrees ....70 degrees out side (roof/attic space is between 60-80 degrees and if all flows right no moisture problems at all.
I have worked on installing proper ventilation on roofs for 30 years and yes some of the stuff he has said is improvements, but also some of the stuff is going to cost people ten of thousands if some of the problems he’s causing are not properly dealt with...
I hope everyone the best of luck as it sucks when someone gives out bad information or does not understand a situation or system..
I have had to teach many contractors, roofers, siding guys, insulation guys the importance and why it’s called a system, it’s been a huge problem when people get the wrong information or when a builder don’t understand the purpose of something...
Now if he understands venting a metal roof, why is he not venting asphalt and other roofs and trapping air up against shorting the life of the singles.. so hopefully this reaches him and he further studies and understand why there is a ventilation system for a roof, attics and it serves a huge purpose to add life (or not let heat shorten the life)
Hint if your singles are curled up it’s the most severe case of too much heat, there are many other signs but that’s the most noticeable...
Huh well at least this won’t be such a huge problem in the future as people get to point out people when they obviously have no understanding or confused (he sounds confused, venting metal roof but not others)
Any further information feel free to contact me as I have dealt with this so many times and have had to help fix so many new built homes as some contractors thinks he has a new way and you need to fully understand the old way before you improve on it..
Yes you can spray foam trusses but you still need ventilation (well it saves tens of thousands over the life of your roof, among other costs) not sure what education he has or what degrees he has in engineering but if you speak to any engineer that knows how, why houses where design a certain way, than you would understand..
Oh I will also ad, a lot of times in construction under trained workers that don’t know why something is done will sometimes not do it right... especially when a siding guy, don’t know his soffit vents are of importance or insulation guy covering up vents or roofing guy not putting in proper amount of vents to create the flow based on square ft, volume of attic, so on and son on...
Well hopefully people will look into the right way and understand you can improve but first understand how to do it right, don’t base improvements on something done wrong as I have heard all his reason of being better as being based on the wrong way to vent (circulate air in a attic) so hopefully he can learn the right way to vent an attic and than improve...
Just hope his customers are not having issues as he is long gone as the problem come up about 8-10 years after in southern states and in cold climates the first winter can cause major problems with ice dams, water leaks so on... it’s better to think smarter work less.... education is very important and sad in construction as most contractors have no schooling only on job training and if it was taut wrong or not taut at all than you will Get this video and lots of guys saying stuff that sounds good but is deceptive and costly to homeowners
Expensive houses are great. Most of Matt’s videos have great advice and are very educational. It is just that as a professional I found this particular video to be well intended, but of poor advice. Radiant heat (long waves) goes through spray foam and blown insulation quite easily. Having airflow next to a radiant flow barrier that is under the roof decking will block most of the radiant heat waves from entering the attic and keep the attic temperature within 8-10 degrees of the outside ambient air temperature and help reduce the heat load to the roof decking which is better for asphalt shingles. I have see too many roofs where the asphalt shingles were destroyed from the thermal mass buildup due to lack of ventilation below the deck and moisture that got trapped underneath. Moisture destroys everything. That being said, now you can go about sealing, insulating and conditioning the attic space where you don’t spend a lot of your time. Just don’t short circuit the airflow under the roof deck. Kudos to Matt for all his fun and educational videos.
you almost never get what you pay for... naive idiot
HickoryDickory86 Bullshit. 250/ft^2 is about 2.5 times the avg here in N. TX. My home would cost me 912k to build with those figures!!! do you know approx how long it would take to recoup the 5-550k delta??? please......
Thanks a lot for putting out this video. i just recently bough a 1951 house in the Brenham Texas area, and my attic looks like the house at the start of the video. Your videos helps a lot as a research and plan on how I want to bring my lovely old house into a modern century.
it is funny watching these past few videos, I have always wanted to buy an older home (CHEAP) gut it and make it extremely energy efficient and all that you talk about are the things I wanted to do to it.
As in Goals vs Systems? ; ) Old homes are great - they even speak.
Me too, because I love the older big trees, and then I see the crappy layout, cut up floor plans, small closets, low ceilings, and shitty mechanicals, and then I decide to build another brand new house😀
It's hard to retrofit a old house and get anywhere the insulation efficiency and benefits of the newer ones, specially if it was built with 2x4 walls and 24" centers, narrow, tall windows,small rooms with up to 4 doors per room, small or no closets and no bathroom to begin with and very crappy foundations with plumbing added much later along with the electricity in the 50's and is over 100 years old and had coal stoves in 1912 to start with. I would have been better off in a double wide.
“Do the right thing” should be the operating rule for every builder. Unfortunately it is not always the case when expensive mistakes are made in choice of materials or construction techniques. But, when the wrong thing gets done, “Do the right thing” means fix it at your expense, not the customer. You passed the test of a builder with integrity. If I were building in your area, I would try to contract with you. Well done, sir.
Roofs should be vented underneath THEN insulation to isolate the space.
Mike Holmes covered this. The top and bottom surfaces of a roof should have equal temperature (or close to it). Moisture is reduced and can evaporate. Snow cover will not ice-up... PLENTY of advantages. Space lost is inches, you just want a channel between rafters, outside the house envelope from wall to roof peak.
Matt, I have a 17 year old house that has conventional blanket insulation on the floor of the attic. When I bought the house 2 1/2 years ago, I was going to add insulation but ran out of budget after re-doing the inside. Now I don't think I will do anything. Whoever built this house insulated the basement in an unusual way. Curtain drains around the foundation leading to one of three sump pumps that never run - one is a grinder pump so I can put a bath down there, one is a sump pump required by Ohio law and the third is a water powered back up pump if we need it and have no power. Then on the outside (poured concrete foundation with brick pattern in and outside) he sprayed the foundation with an asphalt product, applied a mesh product, sprayed again and then use 4" of rigid foam to the dirt line. On the inside I used two coats of Ultra Drylok followed by two coats of SW brilliant white paint and two coats of SW concrete on the floor. No dehumidifier needed, constant 68 degrees year round. Replaced the furnace and A/C system courtesy of my home insurance with a high efficiency system. No round ducts, all rectangular old style but easy to clean. 2,800 useable square feet with utilities
Thank you so much for sharing. Your content is incredibly valuable and appreciated.
I sprayed closed cell right to the bottom of my roof deck in Canada. 1890's home. Allowed me to get rid of the attic all together and open up the ceiling, add skylights. It's been an absolute dream.
Florida is starting to ban or extremely limit any spray foam. You can not spray directly on any exterior wood structure, from the inside. They are finding that when a leak does occur, the water runs into the nail or exterior fasteners and fills the foam with water in those spots. And this develops Black mold. Also, some insurance companies are not insuring homes that have spay insulation on the under side of the roof, if they had a new roof put on after the insulation was sprayed. Because of all the nail penetrations in the foam.
Would probably consider nailing up some higher-density fiberglass instead. Better than dealing with the foam nightmare.
so glad someone is finally talking about how foam can be a huge problem
I always wondered about this as well. Besides high density fiberglass, what other alternatives are there?
Winners have systems! Heck yeah! Love your stuff Matt. I watch them over and over again.
I am enjoying your videos very much. I will be building a barndominium near Taylor this year, and you are giving me good ideas on how to make my house very air tight and energy efficient. I also am going with the little mini air/heat units instead of central AC to cut down on cost. I also thing after the place is done, I won't need much heating and cooling in order to maintain a constant temp.
Fredrik thanks for the input.
Fredrik “
The amount of knowledge in your head amazes me.
This was great!, I love when you get down to the details, keep it coming!
Love your videos, im a hvac installer in spokane wa. been learning lots of cool stuff from your videos that are making me a better installer.
I think I like the idea of the outside insulation roof on icf walls. No spray foam, no drywall.
My place is about 12 years old. We just moved in about a year ago. We are in the Waco, TX area. I have a very voluminous attic and the builder used "fluffy stuff". We just replaced all 15 windows with a very good product that uses argon exclusively in the double pane windows. The window areas are very tight now and I can tell already my cooling bill with me significantly lower this summer than last. The home is a single story 1650sqft home. Mostly brick and some Hardy Board. I'd love to go to foam and "conditioned" attic design AND convert that huge attic space into some living space. I don't want to overbuild for my neighborhood from a value perspective, but we're going to be here for a while and would like to add value and equity with such a conversion. What would you guess might the cost of doing that type of conversion? I might be able to get as much as 400sqft of living floorspace out of our attic. I'm just trying to conclude if it's worth it.
Thanks Matt for everything you do. I've watched you for years now, and every little repair or upgrade I do is based off of your expertise and recommendations. Keep up the awesome job!
My question is would you recommend converting a "production" home in San Antonio with a vented attic, into an exterior insulted home? Or just stick with converting the vented attic into a condition sealed space? Home was built in 2008 and is coming due for a paint job, and most days I'm a few minutes away from ripping all of the Hardie board off the exterior, so I can beef up the air sealing and insulation. Should I invest in this current home, or invest in a new home? The house is two stories, slab-on-grade, with radiant barrier/foil board roof with asphalt shingles.
What did you do?
Awesome video. I always remind people to put in roof vent baffles before spray foaming.
Yikes who would thumbs down this video??
Anyway great info!! I am going to see if spray foam insulation is feasible for my attic. I am wondering though if when I re roof my house whether it would make sense to put the insulation on the exterior and then re roof.
Don’t be bothered by the thumbs down. Almost any video I Post gets 10% thumbs down and 10% of the comments are how I’m “an idiot”. If you’re going to reroof the house, consider and Insulation upgrade on top of your roof, then a layer of nail base and your new roof. No spray foam necessary. The only thing you’ll have to do is seal off your vents and in sure there’s no outside air leaking into your attic. Thanks for commenting! ( and the 👍🏻)
Matt Risinger its prob mostly contractors that thumbs down. He is a very whiny person who complains for no reason. The first attic he showed obviously had some work done after build and they never put back the insulation in that spot. He likes to spend a lot of money that the average person cant afford. I would really love to see him build a budget house.
Really liked the plenum space in the trusses. I’ve designed trusses for 30 years and have not seen this detail before. I’ve learned a lot on this channel. One of my favorite! Keep em coming.
I've slowly come to the conclusion that floor plans should have machinery space and narrow halls to house HVAC duct/plumbing/electrical built into the inhabited levels. Adding 400 sqft into the average home is pretty cheap up front and will pay off massively over the life of the home between energy savings and much easier maintenance.
i'd prefer the box style he showed, where you give up a foot of ceiling space for the mech space
Totally agree!
Those ideas certainly cost less and conserve floor space, and are a big improvement over what is done now, but I just like the idea of being able to easily inspect and work on the vitals, also easy access for potential upgrades or future changes. I guess I've seen too many instances of rodents, who can amazingly manage to appear and be in places never thought possible, chew up insulation and flexible duct work. Having all that duct work effectively sealed from view could well mean chewed up ducting with 5 pounds of rat turds inside it. Maybe these newest very tight and sealed homes are completely rodent proof, but I have a hard time believing that. Also having as much of the plumbing and wiring in an easily inspected area adds to the over all safety factor, but where I'm at, square footage gets pretty cheap once you pass a certain point, and the land to build on is cheap as $5k an acre would be a high price a few miles out side of town. In more expensive markets, it would be a much more costly proposition to surrender so much floor space to machinery.
As an engineer and builder in the northeast, I have always tried to have the air handler and distribution in the conditioned space. This is an energy efficient approach that is easy on the equipment.
Is there any thought on what happens if/when the roof fails and sheathing starts to get wet? Will the spray foam need to be cut out and replaced? Also $250 per SF is very expensive in my neck of the woods. I can build a 2,000sf ranch style home that meets all of California’s building and energy calcs for about $125 a foot. Your permits, and labor rates must be through the roof.
Just think: Crazy California! Haha, you are correct. I’m just wondering what caused that home to have a built cost double what it costs here.
NO house is over has to be demolished you are will not find a leak you will find mold everywhere before you see the leak.
I’m guessing he can build it for a lot less than 250 a foot, but I doubt he wants to advertise that fact to his clients. Which are probably willing to pay in that range. Not that unusual in my neck of Texas for a nicely build home on some property.
As a claims adjuster/ inspector here in Louisiana. I’ve done many roof and attic inspections after storms.
The attics with spray foam are the worst and hardest to find where the water entered because it runs underneath the foam and drips in a completely different area.
Al’s to replace the damaged you have to rip off the entire area decking.
Many times people discover rotted sheathing and rafters which mean it did start from the storm. The storm just revealed it.
Many insurance companies are starting to not cover this stuff and exclude it.
I have open-cell foam under my roof sheathing of a 1945 walk-up attic in Massachusetts. Seven years ago the closed-cell was double the price but was informed that if/when the roof ever leaked (using closed-cell) I wouldn't know until the walls showed signs of moisture. With the open cell the leak would pass through the foam and show on the attic floor or spot on the ceiling downstairs. I know many houses don't have floored attics throughout the country but it was one of the reasons I bought it.
That was cool Matt, I learned even more. I like the "fluffy stuff" reference. ( joe Lstiburek)
Great video, glad to see you adopting attic conditioning. I have been espousing the benefits of attic conditioning to contractors that I speak to and they look at me like I'm speaking a foreign language. I have a question for you, In the attic, can you attach radiant foil to the bottom of the roof before you spray on the foam? I would think this would help a conditioned attic even more by radiating a lot of heat back out toward the sun before it has a chance to make it past the spray foam insulation.
Unvented attic will make comp shingles deteriorate much more quickly, also makes leak detection and diagnosis/repair much more difficult. Something to consider! IMHO It's a trade-off Mr. Risinger
Informative video like always Matt thanks for sharing. I hear people say that "Quality Costs" and may be true but peace of mind and time are priceless.
I see small vents at the base of your “perfect wall” house. Is that a vented crawl space? I thought you said that was dumb to do?
@Baylor Gerardo stfu
We have a 1970 ranch house with a low pitch roof (50x100) with vents/ridge cap/sofet vents. each year we would get 140F in the attic and the AC was on 22 hours per day. About 4 months ago we had open Cell foam sprayed into the rafters (roof decking?) and its about 6-7 inches think. we completly sealed the attic and OMG what a difference. the AC is only for a few hours per day and the noise and dust is way down. also we don't get condensation dripping from the vents! so all I can say is worth the $7K we paid.
With spray foam, what happens “WHEN” roof decking needs replacing? It seems like it could also hide a roof problem?
I'd also like to know if your roof shingles would be adversely effected by spray foaming your roof sheathing. Wouldn't the shingles tend to get a lot hotter in the summer and cause them to curl? A question for a roofing contractor or a shingle manufacturer perhaps.
if u have to replace any wood, u can remove it or cut it out. Or just put a new roof deck down on top of the old one as long as it's not rotted.
@@peteyou2325 no there is no impact on the shingles whether or not you have spray foam in the attic
You're absolutely correct it should be done with baffles between the rafters so you have a small air space between the roof decking and the insulation or put a water screening material on top of the rafters before the roof decking goes on
@@peteyou2325 this has absolutely no impact on the shingles or any other roofing materials but a good question ⁉️
I am not a builder, but I love everyone of these videos.
I love this channel and watch every video. This one brings up a few questions though. Wouldn't spray foam insulation in the rafter bays prevent roof leaks from entering the house and cause a roof leak to go unnoticed until the roof partially caved in from dryrot? Don't you want roof leaks to drip on the ceiling drywall and make water stains to warn of a roof leak so it can be fixed before causing structural damage to the roof sheathing and framing?
Not to mention that you cant recycle wood that has spray foam on it. And imagine that a house full of spray foam catches on fire. There would be a huge column of black smoke billowing off.
A good question, but consider the average homeowner who doesn’t go into their attic space regularly. I recently noticed a roof leak near my plumbing vent pipes, but the decking has already begun to rot. Why didn’t I notice ceiling stains? Because of the partial flooring, and items I had stored up there. Lessons learned, I suppose. In a conditioned attic space, though, it sounds like a hygrometer would be a good idea to detect roof leaks, since it’s open-cell foam. What do you think?
As an insulation contractor and fellow building science geek, I love to see conditioned attics becoming more accepted. I still have a lot of folks resistant to the thought especially with the costs being higher. I am always proud to see a completes conditioned attic and knowing that it will be so much more comfortable than it was previously.
One thing that is making things difficult in our city is the requirement for a Thermal barrier over the foam if there are mechanical systems in the attic. Are you dealing with Ignition and Thermal barrier requirements in the south?
Yes, we have to do those as well. I’m not super happy about them, but I do understand the need and the code requirement. My preference is to use a foam that does not require it
@@buildshow What spray foam does not need a intumescent coating if left exposed?
$250.00 sqf is very north of most custom home budgets. I really like your videos but that statement sounded more in line with a money's not a concern build!
I was thinking the same. 250 is very high. most builders are around 80 to 90.
I would expect a lower cost in other parts of the US. But we need to set higher expectations for performance on our homes. Gone are the days of a home built for $xxx/ft (Insert local average cost). A well-built home with good systems, a thoughtful design, and good tradesmen should cost 1.5x (local average cost). We should be building homes that last a few generations without problems, that are healthy, durable, efficient and long lasting. Build better not bigger.
Matt Risinger, that's great if you can recover the premium cost within a 5-7 yr window but the resale price of the home will only bring $ average of "like" homes recently sold. Unless the owner can document real utility saving to project forward the home will likely not resell for a premium.
Michael Amick yep, have seen this happen to many people that custom built there home. Then bank comes in and says I don't care about your upgrades or how well you insulted, a house in this area is worth x per sq ft and that is all we will grant a loan for. It's a sick feeling to spend $250k on a house where you did a major part of the labor yourself because it was your profession and the bank says it only appraises for $180k.
Hard to say "most" when referencing anything. Our client base covers homes primarily $1.2 -$15 M and we are just south of Austin. Everything is relative .
Love these videos! Always making notes and wish list for a future small home on our southern Oregon property. Love building science!
at 7:12, where is the tie-down straps holding the roof trusses to the headers/2x4's? or is this built AWAY from coast line? Very far away from a coastline?
A ton of comments, nice job Matt. What do you think of this detail from interior to exterior: Closed cell spray foam < roof sheathing < two layers of 2in XPS foam boards w/ staggered seams and tapped on exterior layer < Furring strips < zip system roof deck < two layers felt paper or smart membrane < shingles.
You didn't cover blue tarps, those are popular downsouth... 😂
xephael - just in the guest house.
They're also used frequently in Ohio. Who needs shingles when a tarp and cinder blocks will do the trick? #ihatemyneighborhood
Except for your budget design #3, these designs are not practical along the Gulf Coast for a number of reasons
what reasons? (just wondering - I live in utah lol, so it probably won't apply to me.)
Lizard King right!
Matt, I rarely agree with you as much as I did on this video. I loved the concept on your "monopoly house". I totally agree with conditioned attic space with radiant barrier and a breathing roofing system. I probably would have kept the house a bit lower to the ground and had covered patio, porch where the large windows were to cut down on direct light even though it was a wooded lot. loved the open floor design. People sometimes don't understand cost and quality along with speed of build. you will always pay good money for a real craftsman and more if you want it fast. A well built home like that 1 keep the buyer happy for a very long time only needing to change out the water heater in 12 to 15 years and maybe a paint job. Maybe hire out a reputable handy man to clean the gutters and check your caulking every year. It will hold value and peace of mind is priceless.
Hey Matt great video. I’ve been a long time fan. Big question though if you’re using a spray foam on to the decking of the roof how do you handle venting for the roof?
You don't. The increase in temp of the shingles is negligible compared to a vented attic
I prefer a baffle between the roof decking and insulation this allows air flow from the soffit to the ridge line to keep any moisture water vapor and condensation to vent and dry out it also prevents mold mildew and it keeps the decking the same temperature on both sides to prevent these problems great question ⁉️
Your knowledge is incredible and it's excellent that you share it.
how long do the shingles last . We know that lack of ventilation will shorten the life of shingles in a 70's type attic. How do you detect a leak in the roof? The ceiling foam looks like it could create other problems.
15ish years. And u should be able to detect a leak.
The unvented attic does not always mean unvented roof.
This is what I your videos, not just theory, actually things in practice.
I'm in florida, and I had always heard insulating between the roof rafters, under the roof decking, increases the speed of deteriorization of roof shingles, because there is no ventilation under the shingles to help carry away the heat. Is this not true in your understanding?
Skip Watson so he gets to put a new roof on every 15 years...
grumpybill ... instead of 20 ... yeah, I guess that's a good point. Blessings.
it will. Go metal.
That last house looks absolutely beautiful!
Fire codes?? That much closed cell foam needs to be covered for fire codes in our area. Plus it would cost $20,000 to $30,000 the house will never make up that cost.
What about intumescent spray paint?
@Ego Twistick Not all of us live in California and Texas! Where I live, two story plus a basement is a very common building plan. I grew up in such a house, and I would probably build that way if I were building a new house.
Always like seeing details of sprayfoam attics. Want to do that to my 1969 home. These are great!
I replaced the Bat insulation in my attic with R60 closed cell spray foam back in august and got new 95% efficiency furnace. This year was the coldest year we've seen in 40+ years in Alberta and my bills were half of what they were last year during a very warm year. In fact the last month we've been around -10C to -15C at night and my records show the furnace didn't kick in till 3am. It is so worth it.
You could have also just loaded up another foot or two of fluffy insulation and it would have had the same affect for way cheaper.
Matt what is the process when you have to replace a sheet of decking and the underside has spray foam. Does that foam have to be cut out and reapplied?
Yes, pretty much anything with spray foam has to be demo'd. Seen entire reroofs chainsawed off because the sprayfoam formulation wasn't correct and the house was a toxic hazard and nobody was able to live inside.
Yes
I like the suggestions Matt Risinger has made. It seems to me, logical to put the insulation barriers of a building as near to the outermost "skin" of the building as practically and permissibly possible (ie in compliance with relevant codes).
Placement of any of the machinery, used to condition the living space, within or outside that conditioned space, should be such as to provide the most positive effect on the living space, while allowing the most efficient operation of the machinery. The placement of the machinery would provide the best possible facility for its maintenance and future possible upgrade, whether in a specifically created ceiling/roof plenum space, a basement, an attic, adjunct to a utility room, outside utility room or even a separate building space away from the main building, which would allow for isolation of noise and vibration.
Protection and maintenance of the surface material or skin (cladding) of the building should, I think, be dealt with separately and independently from the insulation of, and maintenance of the living space environment. Cladding protection should be dealt with by the choice of underlayment; vapour barrier choice; facilitation or blocking of air movement & direction by ducting and venting; decking choice etc.. The reverse effect that the cladding has on the conditioned or passive environment of the living space is, to my way of thinking, the only consideration connecting the two.
Books, training videos and youtube videos improve the information base of all people involved in building.
This means owner/clients are better able to discuss various methods, options & costs with their builders, from a much more informed and improved knowledge base; DIYers have better information for their projects; and builders can expand the options for their clients with a sound and qualified knowledge base to support their suggestions.
Obviously, all chosen options are required to meet code standards, and sometimes that may be easier with expanded options, and provide improved outcomes in terms of quality of living space. All final options must be based on sound and qualified information, and be practical for the application. However, "white-boarding" of ideas, whether the application of the ideas are cost efficient, practical or even "sensible", or not, can be the conduit through which best outcomes can be finally arrived at.
Cheers, Peter
250$ / sq ft!? Wow thats more than double any house I know of!!
Not to mention slab on grade. Lol
Ah, you must understand this is Austin, TX, where Matt lives and works.
Average home price is now north of $400k. My 1982 vintage ranch is appraised at $180/sq ft.
That’s what a quality home cost now adays
It's all about where you live. I worked in the San Francisco Bay Area 20 years ago and $250 sq.ft. was bottom of the rung home construction cost. I can't imagine what costs must be like there now.
I'm sure half of that is permits
Great video, very clear footage and really in-depth explanatory commenting. Thanks very much
what about roof venting for passive cooling?
Matt Risinger I really do enjoy your vids. It's amazing what people in Austin will pay for a house, lol. Exposed rafters for $250/sf, not my thing. Now, zoned cooling, mini split heat pumps, yes. All those flex duct runs in unconditioned attics in Texas, throwing money away! The most cost effective retrofit for almost every existing ranch style house (and others obviously) in Texas other than large deciduous shade trees west of the structure is an adequately sized attic exhaust fan. There's better cheaper ways to build, why not??? I'm all about sustainable design. I'm hoping to really start seeing examples from you. It's our future. If you want to build hugely profitable affordable sustainable (non combustible) homes look me up. It amazes me nobody sees it. Plus as everyone transitions to driving EV's, (whether you're aware of it or not) installing rooftop PV solar in Austin and places south and west all the way to the Pacific should be a no brainer. Keep up your great work! You are a great resource. Thanks
Have you done a cost comparison between exterior insulation on the roof to open spray foam on the inside of the attic?
^^^ That is the million dollar question !!!
If it doesn't translate into substantial savings, then these videos are much ado about nothing.
And when there are no efficiency numbers to accompany the videos, that's fishy.
Don't rule out structural insulated panels. They are strong and very energy efficient.
No offense intended but when you spray open cell foam insulation it should be sprayed evenly and not exceed past the trusses. You should see the boards after expansion. You end up with a r value of 32. The foam should be relatively flat. That's how we do it up north. Love your show man keep them coming. I'm a builder who appreciates outside advice or better ways for building
Learn a lot with every video
Spray foam can be the Devil's work, specially considering the adventurers in the business. Mixing chemicals like that, when improperly sprayed, can cause health issues in future residents. But getting insulation under the roof is a must! I really appreciated that wrapped house with "external" insulation as a reasonable and practical solution.
I’ve heard foamed roofs can make the shingles and wood buckle due to heat. Any truth to this?
Yes, talk to you territory representative from GAF/Certainteed/Owens Corning
Yes spray foam sucks over the long term. Asphalt shingles have little or no warranty when installed over a spray foamed deck. In hot humid climates it will cause the decking and shingles to buckle. Spray foam is the best worse thing you can do to your home. Run from any home that has it especially in a high humidity location. Additional mechanical systems are required to remove moisture from the attic space these systems will add $10,000 to the cost of the home and require regular maintenance and have a expected life span of 10 years. At which time you will spend another $ 10,000. The best bang for your buck is R-38 insulation and a well ventilated attic. I only have experience in Florida with the spray foam. This stuff is a maintenance nightmare will be compromised at the first roof leak that needs to be found. Your roof will probably have a shorter life cycle due to the heat building up in the decking and roofing product instead of dissipating into the attic space and then vented out. DO NOT USE THIS
PRODUCT ON YOUR HOME THE ONLY POSITIVE IS A COOL ATTIC EVERYTHING ELSE IS A NEGATIVE. So for 1/20 the cost of foam go with R-38 batts or blown insulation and use the savings for a pool, man cave vacation all led lighting outdoor kitchen,solar panels etc etc the solar will pay you back for years to come. The foam will cost you for years to come. This is my opinion only from over 40 year in the HVAC trade. Google spray foam and roof warranty. This alone will cause you to run from this stuff
Matt, love the video. Appreciate you always having these very well-informed discussions.
How do you find a roof leak? How do you even know you have one? All roofs leak it's just a matter of when.
Open cell foam doesn’t hold water ...water will come through it and you’ll see where it is coming from. Open foam is easily removed so you can repair that area. Closed cell foam is NOT to be used in the attic because it will not let the water through which will cause rot in time.
Some of my family still lives in Poland. Most homes have stucco on the outside, about 20 years ago, one of my cousins was insulating his home from the outside like you have shown on the last home. They used large sheets of 2” foam board and attached it to the outside of the home. What are they doing today, who knows, haven’t been there since 2005. The home I’m talking about is in Rzeszow, Poland. Most homes are built from blocks (concrete, clay, etc.) and heating systems are hot water. Most homes have no insulation, unless they are built within the last 10-15 years. Many homes are self contracted, and usually are representative of where the person lived outside of Poland. Comments?
Great video, but don't forget to warn people that spraying attic foam can be "toxic" and end up contaminating the whole house and eventually have to remove the whole roof!
This is just false and misleading.
Cool deal! I love the last house that you showed. My whole life I have been wondering why we always had to put insulation on the inside of buildings. It never made any sense to me. Thanks for showing that you really can insulate out side of the box. :-D
Cause hail and storms.
4:21 you talked about doing it, but it wasn't done, so really you've created a conditioned space which is not ventilated. A closed sealed area, with no ventilation. Professionals like to call that a man trap, where people go to die from asphyxiation.
Good rebuttal.
I did a conditioned attic in Phoenix Arizona 10 years ago and they thought i was nuts! It was convincing the building department to let me do it was the biggest challenge.
Matt....any thoughts on retro fitting older homes? Is it viable? 1962 ranch.
Do your retrofit when you are about to replace your roof and maybe go with a standing seam metal roof like matt did on that monopoly house. Your walls? are you brick? Just sticking my nose in your business.
I’m up,here in northern Illinois preparing to build a new home. My concern is roof deck temperature with this system since ventilation has been eliminated.
Thanks, great channel
30-50 years ago we did not have the foam sealer
Robert Fulton we sure did
And your family's health was much better for it.
Hey Matt! Great video as usual. Always entertained by negative posters and people who do like the videos...
wondering if you might do a video on strength of using foam and also a video for us down here in the south of strengthening the building for hurricane resistance?!
Gasp! Toward the end of the video, did Matt really say $250/sq. ft. was a cost efficient figure???
"North of"
williamhoodtn Yeah, that might be typical in California or New York, but it's damed expensive in Texas.
Here in Ga too. You could probably cut cost with 2 x 6 exterior framing and using that 3" of insulation board he used but the wood will telegraph some outside temp to the inside. The roofing system was spot on.
I payed 150k for my 2080sqft house.....yes i have the fluffy stuff....that means i payed 72.11/sqft......with his math id pay 250/sqft.... Or 520k for the same size house....a 370k difference....over 30 years id need to save 12,333/year in energy savings(this doesn't even include the financing of that extra 370k over 30 years)
williamhoodtn nothing this guy does is cost effective
I like the long form. You should build up north in the summer so you can teach Northern folk how to build. We have a lot of problems with all the snow and temperature differences we get. Plus basements!
15:54 looks like a tuna can to be honest with you, great video about insulation though
Great video. I really enjoyed the discussion. Maybe you could make a video and talk specifically about how you would take one of those “dumb” houses and convert it into a smarter, more efficient house. What are the systems and ways to correct the problems and are there things that just can’t be fixed. Thanks
I'd like to share my experience with high efficiency furnaces in unconditioned spaces and the lack of local codes and knowledge. It's almost comical but these poor home owners are the ones having to pay for mistakes made during the new construction process.
You're right they pay the cost of contractors short cuts poor engineering and poor quality in craftsmanship it's all about as cheap and quick as possible for as much profit as possible they don't care about their customers even after the sell in resolving problems it's a cheap bandaid fix maximize profits is all they are concerned about
It is nice mounting the utilities up in the attic!
But by insulating the underside of the roof, you will cook the shingles - best to use light colored shingles in that case. Alternatively, keep one inch of air space between the insulation and bottom of the roof with vents at the bottom and top of each channel between the rafters to allow for venting of that small air space. You can make that one inch of airspace using XPS (a lot of work) and then add more insulation below that to get the R value up.
What is "XPS"? Where are you, geographically? It matters.
Matt, you could write a book . I suspect people would be queued up to buy it.
Very kind! I’ve been thinking of doing some in depth Training Videos. Think the market would respond to that?
Matt Risinger I think it might, though I'm certainly no expert in the construction field. But I think that even if just DIY-ers pick them up, there is bound to be some market for such videos.
That said, I would hope that the more respectable contractors would pick them up as well, and maybe use them to train their new recruits (or even the old hats for particular, challenging jobs).
Matt, how about putting in a few numbers so they know the why?
Even then, still an uphill push (currently having difficulty enacting ECMs that I have shown to be very effective using eQUEST).
I would watch, never know what you missed and could learn.
Martin Holiday of GBA has a great book.
You have had much time using spray foam? I have found on paper it looks good. Any leak will go unnoticed until it is too late an by to late mold growth so damaging beyond repair the whole house has to be demolished.
Inexpensive @ 250 sq ft??!!!!? What the
Fascinating stuff Matt. Thanks for sharing this...gives one much to think about.
Spray foam is fine unless you get a roof leak.
Or a fire!
I wish you went into more detail about pros cons of roof leak issues with open vs closed spray foam. Also, is 90% efficient ac that important when you put money into a vent free attic? More detail on the ac noise dampening would have been interesting as well. Lastly, what type of foam does not need a thermal barrier?
Thanks for your videos!
So it's ok to put spray foam directly under the decking of the roof without an air gap?
No it's not ok, 1) voids shingle warranties, 2) tends to trap moisture or condensation against wood, problems 5 years down the road. We are just beginning to see issues with spray against roof decks sprayed 5-7 years ago.
I do not agree with Matt on this spray on insulation direct to the sheathing. The APA (American Plywood Association) specs out requiring that one side of the OSB or plywood have an air space next to it to allow moisture to escape away from the wood. Radiant sheathing will also require that there be an air space next to the foil laminated side. I would recommend a ventilated radiant barrier roof deck using a double deck with furring strips or installing a full coverage baffled underside to a continuous vented soffit and up to ridge vents to achieve a 1/150 nfa. Then a foamed underside could be achieved. The direct foamed decks are a nightmare for finding leak issues and if the decks have to replaced, oh boy.
I believe that GAF has a really great vented roof decking product that would offer the best of all worlds.
Not true. It doesn’t void warranty and even if it did when was the last time you heard of a collection on a shingle warranty.
The only issue with Moisture is with high humidity in the house. Use a dehumidifier if you are in the South and/or add a small amount of AC supply
Yes it’s ok.
I'm not a fan of spray foam as the primary insulator, but IMO it can play an important role for air sealing. That was a very cute house though, Matt. I love the exposed look, which is much more interesting and beautiful than drywall.
what about the health issues from isocyanate..the spray foam..aka polyuethathane..not saying it not great for insulating..but that is only part of the story..
That's an amazing house. Thanks for sharing the construction tech behind it.