Spray Foam and Radiant Barrier: How NOT To Do It!!
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- เผยแพร่เมื่อ 5 พ.ย. 2020
- At Smith House Company, we love learning about the science that makes our homes more resilient, functional and beautiful. Learning is a never ending process, and in this episode Jordan walks us through why he changed insulation strategies mid-build. For more learning opportunities go check out www.mtcopeland.com .
Radiant barriers work by stopping radiant heat from emitting into the attic space. However, in order for a radiant barrier to work, there must be an air gap between the barrier and insulation. Because the attic on this home will be finished living space, we will have cathedral ceilings throughout, resulting in insulation between rafters instead of a attic floor. This wouldn't be a problem, as we could leave an air gap between the insulation and TechSheild Radiant barrier and have the bay vented from the eave to the ridge. If we did that though, we would be relying on the drywall to be our air barrier, and Jordan was not comfortable with that solution.
So instead, he took a step back and decided to spray foam the roof deck, eliminating any benefits of the radiant barrier.
Lesson Learned!
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Good job Jordan, the industry needs more contractors who actually want to complete a project to the best of their ability. Great video, very humble, we all appreciate your work ethic
excellent walk through of the problem and why you changed your mind, thanks.
I tried it and I liked it! We I have used open cell spray foam on tech shield with vent baffles to allow the hot humid air to escape through ridge vents. I compare it to the effect of backer rod and caulking. The vent baffle (like backer rod) not only creates the 1” air space that tech shield needs, but it isolates the spray foam from the roof deck. Like caulking, spray foam can only stick to two slightly moving surfaces (the rafters in this case). When they are applied to three surfaces (2 rafters and the roof deck), the foam (or caulking) would only be able to stick to 2 of the surfaces and would delaminate from one of them to allow the rafter to expand/contract. Thereby leaving the air gap some say happens over time with spray foam apply to the underside of the roof deck. We have had amazing results and ACH sub 0.5!
Great video, thanks for taking the time to make it!
I’m doing the same thing right now. I used tech shield, but have now decided to spray foam. The tech shield was actually cheaper than regular decking when I bought due to the lumber prices at the time so I guess it worked out in the end.
Love it, man. The simplest answer is usually the best answer.
Good Stuff, I'm going through the same thing with my shed/workshop. I put r-19 bats on top of radiant barrier. It didn't do anything except transfer conductive heat. I ended up spray foaming it. In the Texas heat, it rocks and works like a champ.
Great discussion. Appreciate the insight and candor
Jordan not only a you are talented contractor you would make a fantastic educator or let me say you already are because you're helping many understand with your review of several forms of energy from the Sun, then going forward into the technical details of roof construction facets during home building: thoroughly enjoyed it (5 stars) also I suppose you could use a product like Versatex Canvas Series PVC which I like to use instead of any sheet rock, again more expensive, yet well worth it: take care, JD
Thank you! I like closed cell but I worry about the gas emissions if not done properly.
I went through the same process and ended up doing the same thing in my attic, except that I removed the radiant barrier, first. I think when I replace the roof, I'll add radiant barrier to the top of the sheathing, then an air gap and another layer of sheathing with radiant barrier on the bottom.
@ Jordan Smith I watched this video because I'm trying to figure out a similar challenge. I am trying to get the most protection I can in a 2.5" thick stud bay against metal with shiplap as the interior wall. My thought was to use 2" of closed cell spray foam to deal with the condensation and conduction and trying to add in some form of radiant barrier to the mix (one of those multi layer insulation insulation products). If I put the radiant barrier first, right up against the metal then spray foam right on top of that, then the layer of the radiant barrier that is directly in contact with with the metal and as well as the closed cell foam would not be working for me (only the inner layers of the MLI is beneficial). But what if I put the radiant barrier in the gap between the spray foam and the ship lap wall? Thoughts? Although there wouldn't be perfect even gaps in between the 3 materials, a vast majority would have a gap of one sort or another. Thanks for the video!
Even though you sprayed the foam onto the foil face without an air gap I think you would still get the emissivity properties and reflect radiation back towards the sun. I realize you now have conduction working against you. Very interesting Jordan!
I have been looking into using a baffle that you can use in conjunction with closed cell spray foam insulation. This would allow for the 1"-2" air gap to vent the roof, but also be sealed by the closed cell spray foam insulation used on the baffle. Does this solution sound like it would work and maybe be the best of both worlds?
You should have installed a layer of rigid foam an inch away from the radiant barrier, then you could have sprayed foam over that to air seal.
Rigid foam is by far cheaper than spray foam and allows for a more efficient system. I use both spray and rigid because they both have their advantages and benefits.
You are Correct.
Yes, this guy must sell open cell foam because it’s obvious to anyone that he should have done what you suggested. I feel better having a vented air space next to the foil in case any moisture gets up around the roof deck. It can dry without the mold possibilities . The vented roof doesn’t even have to be open without obstruction as roof felt can allow moisture to pass.
Yup! I did a porch cathedral ceiling with a 2 inch air gap between under the roof sheathing and the first layer of reflecto bubble foil (reflective foil side facing up towards the roofing sheath.) Then the next layer under the reflecto wrap was 2in X 3 layers of blue styrofoam where each layer with joints was sealed with caulking or Great Stuff foam (for wider joint gaps)
Then another layer of reflecto bubble wrap on the 3rd styrofoam layer, with the reflective side facing down towards the inside of the living space, then strapping 1 inch thick, for air space for the radiant effect to take place then ceiling planks were screwed onto the strapping. Voila! Super air tight and and insulated. The light fixtures never penetrated into the 2 inch air gap and I had a ridge vent and soffit vents for air flow in and out of ridge vent.
Next project is to do the same in the attic as was done in the porch cathedral ceiling, with a skylight too! Cheers, stay safe from Atlantic Canada during covid
Interesting solution. Do you think this would work for an old attic conversion? (into liveable space). 6" rafters not leaving much room for play.
@@diamondbracelette Hi there. That is what I had, 6 inches. I put 3 layers of rigid foam with the 2 inch air gap and the reflex foil layers. The last 2 inches of rigid foam were screwed into the edges of the 6 inch rafters which added the additional 2 inches to the 6 inch rafter. With out a visual it may be difficult to explain. Therefore the living space height will loose 2 inches if you add the additional 2 inches of rigid foam to the existing 6 inch rafter. This means there is 6 inches of rigid foam total. If you do not want to loose the 2 inches of height room, the only put 4 inches of rigid foam that would be flush to the 6 inch rafter. Hope that helps. 💪😀🇨🇦🛠🪚🔨
@@MegsCarpentry-lovedogs @Meg'sCarpentry,lovedogs Thanks!! So what you just described was the attic job that was forecasted in your original comment, I believe. And yes, the layering does make sense, especially regarding the outer layer that would sacrifice height. I truly have none to sacrifice! For the first job, you mentioned the radiant barrier (reflecto layer) being installed iver the last foam layer (reflecting inside). What was your thinking behind that second layer? And sounds like you didn't use this second radiant barrier in the attic? Also, in considering R values did you opt to use the foam board versus spray foam due to the spray foam not working--install wise-- with your system? Despite the greater R value from spray foam? Oh oh oh! and also, you mentioned 2 inches air space. I understand that that's needed for the radiant barrier to work, but read that an inch is enough. Is 2" better? I have no ridge venting either. Share all secrets pls 😂
@@diamondbracelette Hi. Difficult to share details without visual. To answer your questions as best I can, You will need ridge venting otherwise all of this insulating work is useless because you need to have the passive air flow flowing in the 2 inch air space. Yes, 2 inches, NOT 1 inch. Yes, I did use the second radiant barrier opposite application to the first radiant barrier that had the shiny surface facing up to the sky and where 2 inches of passive air flow flowed over it to the ridge vent. The second radiant was located on the last installed ridge styrofoam but this time the reflective side was facing down towards the floor and the strapping held it also in place, 1 inch strapping, because the strapping is what one screws the ceiling planks on to. 1 inch space could be used in this application because there is not a air space needed for air to flow to the ridge vent. Two different scenarios to pay attention to. The purpose of having the second reflecto layer is to reflect heat that rises from the room BACK down into the room. Reflecto is all about reflecting heat. So the first layer reflects it back into the 2 inch air space to be passively flowed out to the ridge vent and thus keeps the shingles from over heating as well, and the second reflects the heat generated from inside the home back down into the living space. Using as much science heating theory as possible so in a cold Canadian Winter we stay a bit warmer from the reflected heat back down from the ceiling. Hope that makes sense and helps. As for spray foam not being used, once you put spray foam in it is impossible to remove and I like options in case any of the rigid foam needs to be removed unexpectedly. Also, if you use spray foam you have to have additional equipment to use, which means renting and a lot to that time to go get it and return it and clean it and, yada yada yada. I live in the country so super practical to just take measurements and cut the rigid foam on the work bench and get on with the big task of getting all that rigid foam in stalled and tightly sealed. 💯🇨🇦💪
@@MegsCarpentry-lovedogs Incredible reply! Huge thanks. This goes a long way to helping me solve my particular riddle. Northeast US, climate zone 5 I believe. Looks like my next step is contact a roofing contractor to assess if soffit vents and a ridge vent is possible. Shallow overhangs and no ridge board but my first take is that it could be doable. Cheers :)
Question, I have a new build house that I am considering spray foam on the rafters. I am using Zip R6 on the exterior sheeting and rockwool R19 in the stud space. I just want to spray foam the roof system. How do I vent the space? Eave vents and ridge vent? Do I condition the space with a supply and return from HVAC?
Having been to a top 10 school and graduating with a degree heavy in Chemical engineering classes, I can say that the narrator's 10 second explanation of radiation, convection, and conduction is amongst the best I've heard.
Edit: grammar
I guess I am confused about the use of air sealing on the outside and then going back with spray foam. It would seem that if you already have the air seal on the outside, that the use of the radiant barrier, then fiberglass would cover all of your bases. With the spray foam, as you stated, you lose the radiant part. In short, I am confused why the spray foam is better. Thanks again for another great video.
Did you consider calling TechShield, or Matt R or one of the Building Science contacts he uses, about leaving the air gap between the radiant shield and the FG batts, without the eave and ridge vents, before doing the spray foam? I agree with what you said, that it seems that should work as long as the moisture seal is good.
How does the venting work with the hip/ valley behind you?
When i redid my roof, i had ridgevents put in, thinking i was being smart and thinking ahead when I redid my living room and attic space to add better insulation. Turns out I was going to do sprayfoam and not have to worry about a hot attic in the summer. Obviously ridgevents aren't that expensive, but i was bummed that i essentially wasted that money. I have a 1200 sq ft garage with stud framing and trusses. What do you think the best way to insulation the attic space is? I don't have anything on the ceiling as far as drywall goes, I've heard about people using foamboard, but that's not code, apparently. I thought about rockwool for my walls, but fiberglass batts with a radiant barrier in the attic space, but I'm not sure quite how to do the radiant barrier. Any input would be appreciated. I'm in ClimateZone 4.
Curious what you did. Climate zone 4 here also. Currently I plan on using tech shield, smart baffle, and sprayfoam in a cathedral ceiling. 2x10 rafters
I have spray foam in my attic with no radiant barrier. Is it a good idea to spray the foam with radiant barrier at this point?
Thanks
What region are y’all in? Thanks for the videos
Can you do blown in fiberglass loosefill into roof deck? we have unvented roof drywalled with heated attic rooms. Will blown in fiberglass csuse any problem to unvented roof? Anybody knows?
Fantastic Job Jordan, where in Texas are you from? I have a attic project, I am wondering if I can hire your company to build living space up at my attic? I am in Sugarland, TX
Jordan, is there any issue with panelling over top the spray foam ?
What if I laid 1" foam board over rafters vs in? It would be a 6" air gap to ridge vent.
Good for you Jordan. I don’t know what you “should” have done, but I appreciate that it was your best self making that decision. We do not live in a perfect world. Please God and you may need fear no man.
I don’t like ridge vent systems for a couple reasons, one is the idea of letting damp air into my attic isn’t good and 2nd is I don’t like holes in roofs. Iceneyne foam is amazing. It might be rated at r21 or r38, but the real number is higher but there’s no way to rate it. In my house, in south Florida, I’ve had my power go out and the house go from 76 deg to 80 deg over 8 hours in the middle of the day. I use it in all my custom homes. There’s also a noise factor to it. Houses with the foam are a lot quieter than the same house without it for some reason. It just seems to absorb sound. It also makes it easy to work in the attic since there’s no insulation to dig through to find a wire or add a fan or light fixture. It’s not cheap, but it will pay for itself in electric savings, but there’s more “quality of life” value to it than just saving money on electric
Their is just no way to seal your house tight enough for this way of insulating. Maybe for a short term and when you seal it up like your trying to do, you have no way of knowing until its to late that you got mold. You build for known inconsistencies in construction.
Did you insulate walls or just attic - South florida build here with basically no insulation in walls and typical blown in fiberglass in ceiling but considering having roof sprayed and removing fiberlgass. Appreciate any feedback
I know my suggestion is after the fact. What if you would have put pvc pipe under the insulation on your roof and gone up to your roof ridge prior to shooting the foam into the remaining area? That would give you your “gap” yet allowing for the sealing of your layers of insulation. Yes, I realize that would be more labor initially but would you get the benefits of both. Just an idea.
why didnt you just use the air gap with attic chutes then sprayfoam over that? Or use sealed poly for air barrier ?
I must say, I'm glad we are learning how heat works... But we are missing a few things here. (not being rude just pointing out somethings) Radiant barriers DO reflect not absorb (rejecting heat in this case is reflecting heat unless you can draw that heat away). Absorption is what something black would do (although everything does absorb radiation in varying amounts). Radiation IS light, mostly infrared. Although radiation is a longer wave length it can't penetrate the metal roof. All things emit radiation, as everything has heat. More heat = more radiation, sometimes into visible light if hot enough (like the sun). The way a radiant barrier works is by reflecting the radiation back to the surface that emitted it through a gas (because they don't absorb it much or through space). if you don't have a gap you don't really do anything. The gap can also be used to cool the surface. The radiant barrier should be pointed in the direction of the heat source. An air gap under the roof deck with a radiant barrier beneath it would be a better design. Or put the metal roofing on furing strips with a radiant barrier roof deck. If you live in the north an attic facing barrier would help a tiny bit. But shouldn't have anything in front of it.
I put the spray foam against the roof deck and the radiant barrier on the underside of the rafter, may be overkill but hoping it helps with energy savings
Does this work? Can you just spray the completed spray foam with radiant barrier?
Thanks
Techsheild will still add a little r value and it will still reflect heat. I see it as just increasing benefits, maybe not cost effective now but over decades will help energy use.
Does the spray foam adhere to a radiant barrier?
Keep out the heat - keep in the heat. Keep out the moisture - keep in the moisture. Spend lots of money and in the end doubt your process. Reminds me of a girlfriend.
I think Jordan would be fun to talk to after a few beers when his "I shouldn't say that" filter wears off. I get worked up about attic sealing/ventilation too...so much more going on than a dumb person would assume. :-)
What is the best way to insulate an A-frame house roof without an attic?
How are you going to ever replace the roof decking in the future if you foamed directly to it? I hope you put roofing felt/paper/underlayment something, so that can be replaced when water will or could eventually damage it.
Are you talking of a leak? I can assure you I have put in a couple of pieces of sheeting here and there on a spray foamed roof but NEVER has the entire decking needed removed. If you needed to remove ALL decking there was another problem and nothing to do with spray foam I can assure you.
@@davidburkholder7360 well yes roofing fails over time 100% of the time, hence why roofing gets replaced every 20 or so years. All decking, a few pieces of decking a piece of decking… The point is without a break between one component to another. When you have one material that will likely need some repairs/maintenance or replacement, then how are you not passing the buck? I’m not saying spray foam is bad. The install of spray foam doesn’t account for the future issues, maintenance or expense of the roofing. Roof decking does have to be changed from storm damage in my area often. Why would it matter if all or some needs to be changed? The question is if any needs to be changed how the heck do you ever dream of removing it for repair, when a simple layer of felt would create a break between material and help the next contractor down the road someday.
You call them eve vents rather than soffit vents in your area?
There is no question that spray foam is the best solution for an occupied room with a cathedral ceiling. Ideally closed cell. Your radiant barrier under foam will, at least, make pulling the sheathing off quite a bit easier. Otherwise big chunks of foam come with it. Hopefully in the far future. As far as radiant barriers for conventional attics, I think the benefits are marginal at best even though radiant transfer is minimized. Foam can take a 125f attic down to 80f by itself.
Nonsense. All that was needed was spray foam. I have done many a new roof with spray foam and never a problem.
@@davidburkholder7360 “at least”.
Could you not have left an air gap by using 1/4” ply and 2x2’s then spray foamed.
Yeah but you are adding significant labor and cost
Why did you use open cell foam on the roof, at least that's what it looks like?
How would it work if you wish to spray foam the whole ceiling what's no ventilation
Radiant barrier shouldn’t be a replacement for insulation but it is a great supplement to it. Have you guys tried the double bubble foil? If it is directly facing the space it should do well.
Did I miss something?
What's wrong with venting the roof with the plastic baffles on the sheathing and spray foaming?
Also, I'm a Canadian. First thing I thought of was to use vapour barrier!
i think he didn't put a vapour barrier between the plastic baffles and the foam...but yeah i guess it should work. because what you want to shield against convection is your insulation, not your house
@@TheIcyhydra he didn't use plastic baffling, he spray foamed right up to the reflective sheathing.
To my understanding, if you're going to use batts for the insulation, you get them 2" shorter than the depth of the rafter bays to leave a gap for roof venting. This was his original plan. But then he was concerned about air sealing. Normally in my parts (it's code) you'd apply a layer of poly sheeting after the insulation which is the air control layer. Then the drywall on top.
But if you're going to spray foam, there are the plastic baffles that hold off the spray foam 2" away from the sheathing to allow a channel for air venting and then the closed cell foam acts as the air control layer.
@@beurky yeah... they'd use plastic baffling on concrete too near the liquid barrier, it's pretty similar in term of diverting a fluid
I tried it and I liked it! We I have used open cell spray foam on tech shield with vent baffles to allow the hot humid air to escape through ridge vents. I compare it to the effect of backer rod and caulking. The vent baffle (like backer rod) not only creates the 1” air space that tech shield needs, but it isolates the spray foam from the roof deck. Like caulking, spray foam can only stick to two slightly moving surfaces (the rafters in this case). When they are applied to three surfaces (2 rafters and the roof deck), the foam (or caulking) would only be able to stick to 2 of the surfaces and would delaminate from one of them to allow the rafter to expand/contract. Thereby leaving the air gap some say happens over time with spray foam apply to the underside of the roof deck. We have had amazing results and ACH sub 0.5!
@@HeirloomBuilders do you need vapor barrier in your design? My contractor told me to remove anything that preventing air flow
Yes, I learn something... I know spray foam will work but I like to see the ceiling with batt insulation
I'm curious as to what percentage of the heat will change to conductive heat. I just can't see all of it conducting, especially through a material that wants to resist heat.
I understand why you didn't try a hybrid system, but if you were, I would have done it one of two ways. Use something similar to those awful attic air deflectors to create the gap and then spray foam to create the air barrier. The other way would be to put sleepers down on the roof deck (using standard sheathing for the roof deck) and then putting the tech shield on top of the sleepers. In both cases though you would still have an eve and ridge vent. One other way that comes to mind without having to use tech shield is to just put the metal roof on sleepers and allow that to vent.
Smart guy.
Did you consider installing the techshiel upside-down, with radiant barrier on the outside? You would not get the ~90% air gap you might have had with no spray foam, but you probably get some % of an air gap. Also, did you consider installing a separate radiant barrier on the bottom of the rafters, before installing sheetrock? This should provide an effective radiant barrier, although it would be inside the building envelope.
I LIKE THE PERFORMANCE OF SPRAY FOAM HOWEVER being a green builder I personally think that the chemicals used to manufacture the foam are highly toxic and dangerous... also there the little issue of the installer it's the manufacturer and if the mixing ratio it is not 1-1 for whatever reason (clogged nozzle or any other of the 5 to six factors that have to do with it) it could fail and you would not realize it until it's to late and material it's venting all this chemicals in your house... safest choice it's use something else... thx love the chanel and all the geek info.. keep it up
..
2" closed cell and fill the cavity with blown fiberglass or mineral wool.
Should the shiny side face the sun or into attic. Logically shiny side needs to face sun to reflect radiation. In Australia everyone makes this mistake
How is a foil supposed to reflect sun rays if it faces an attic floor ?
@@rj.parker if radiant heat is not reflected it means it converts into other types of heat and partially heats osb and shingles on top and partially air in an attic . Ok we get less heat coming into an attic but now we expose shingles to extra heat which will lower a live span of a roof . My plan is to buy a foil, roll it out on the attic floor over insulation and a foil would reflect radiant heat outside of leaving area for the most part without converting into other types of heat
@@rj.parker the attic fan that I have paied $270 for will handel dust
I personally would have nailed a 1 inch foam board one inch off the reflective material and then sprayed closed cell spray foam over the foam board. You would have gotten an R value of 42 +\- 1, additional structural integrity by the closed cell, vapor and air barrier, and would still have your reflective ability all at the same time.
You did what you thought was best for the situation at the time. That’s what matters.
Seems like if the radiant barrier is attached to the plywood it would conduct, I do think radiant barrier attached to the bottom of the truss would be way better.
Won’t the radiant barrier still reflect some heat? If I put a mirror in the sun, it reflects heat. If I touch its back, it will conduct heat to my hand, but it’s still reflecting heat from its surface. It might not be as efficient and it might not be worth the money, but I don’t think it does nothing.
I don’t get why you have to seal the sheetrock. All Attica that uses batts and vents don’t need special sealing
You definitely took that extra expense well. How many days were you counting those thousands of dollars out of your paycheck lol... We've all been there.
I just heard that the mortgage companies may not let you sell your house with that stuff on it and may make you take it down.
I must say that there is physics that you do not understand and it is not easy for anyone to understand it themselves. However, emissivity and reflectivity are physical properties of the material/surface and do not depend on the position of the material you place next to it, such as air, wood, foam, etc. There are many other variables though such as the wavelength of radiation, the spectrum, and the temperature of the sun and other surfaces. In short, whatever you add won't hurt. However, speaking of cost, metal roofs are a radiant barrier ithemselves, and adding an air gap with proper ventilation is more important than adding another radiant barrier.
Guy admits that he made a mistake, gets a thumbs down. ???
Why would'nt you put a light in the attic space or 2 so you can see and seal it yourself soo you can see!
If you can afford closed cell foam, you're probably building with Insulated & Taped Zip panels which drastically cuts down on air transmission into your home along exterior walls. As for your cathedral ceiling, there's virtually no openings, so that argument flys out the window. Now, spraying your hip walls makes a lot of sense. But having spent the money on the upsized 2x10s & TechShield, you should have gone with the R30 faced batt. Otherwise, you shoud have just stuck with 2x6s, assuming they supported your loads, and then sprayed them with foam. If you're not going to leave an air gap, then you're throwing money down the drain with TechShield. Just my $0.02.
Jordan, ppppffffftttttttttthat was a very long video.
If possible use graphic images and numbers so the story can grab the viewer more.
I agree. The presentation should have been tightened up, and he should have shown us what the Tech Shield looks like.
What is Jordan going to build next, how not to do it?
Hey Jordan, i would love to hear your opinion on what i figured out on this house i did a video on:
th-cam.com/video/qSuK-fBWE4s/w-d-xo.html
Couldn't you have used a Styrofoam baton behind the foam?
"Zero good". Spin it as insect protection? XD
I love learning all this stuff. After high school, I wanted to build houses but because I live in a border state all the construction jobs went to the illegal aliens. Instead, I went to school and then into medical research. (Thank God for my brain). I still wish I could have gone into the building trades. Don't believe it when people say they're only taking jobs people don't want.
Where is my comment? Did YT delete it?
Illegal aliens steal jobs. Sad but true.
Love your videos, but I must confess that I am in the anti-foam camp. It's as if nobody at the Build Show (or you) has ever remodeled a house with 15 to 20-year-old foam! It disintegrates, it dries out and crumbles, it pulls away from the substrate, it is useless for insulation and even more useless for air sealing after a few years. Even the super-green made with castor seed or soy oil products outgas chemicals from day one. This is an inherent property of the material. It always outgasses. There is not a single manufacturer that will warrant the product for 50 or 100 years (like Sega tapes do) because it is a temporary material. I strongly disapprove of installing an essential component of the house that is only temporary. Second, it is a fire accelerant. Did we learn nothing from the Hindenberg disaster? It is unwise to wrap fragile flammable wooden structures with fire accelerant. Foam insulation has proven - tragically, in hundreds of major fires worldwide - to increases flame spread and therefore the lethality of the fire. There are much better solutions than foam. Passive House recommends dense-pack cellulose - the cheapest insulation out there. With your rafter depth, you would have achieved R38 for the roof and saved a ton of money - and it would be PERMANENT!
Yeah, seems like you're gambling with spray foam. Maybe you get a good installer and it's mixed and applied correctly, or maybe you don't. If you don't, good luck getting anybody to fix the very costly mistake. And good luck with your health...
I feel the same way... I don't see this stuff lasting decades? What a mess in years to come...
All comes down to the quality of install. Foam should last the life of the house if installed properly. The things you mention like off gassing is a result of an incompetent installer spraying off ratio. Pulling away from the substrate is either temperature related or the substrate having contaminants that don't allow it to adhere properly. It's a liquid adhesive
@@DTWCT No. I am terribly sorry to disagree with you. Foam has a lifespan of about 15 to 20 years. Just look at ANY remodel of a 15- to 20-year-old house with shrunken, crumbling spray foam insulation. It is a toxic crumbling mess. Every time. In fact, Matt makes allowances for that in his own home rebuild project. When he put foam insulation on the roof, he carefully staggered the seams because foam always shrinks; even the foam manufactured as boards in a factory with carefully controlled ratios.
I am sorry, Mr. Kiley, foam always shrinks. All two-part foam installations decay in about 15 to 20 years. That is inherent in the material. This also applies to 'foam in a can' for sealing small openings in the insulation at window or door frames. Read the fine print in the manufacturer's information or the MSDS, you will discover that I am not exaggerating. So, no. It does NOT "come down to the quality of the install."
A house should last for a hundred years with only routine maintenance, two hundred with any luck. Foam lasts for 10% to 20% of that time. It is not a durable permanent construction product and it outgasses toxic chemicals for its entire life and the foam residues are also toxic and difficult to dispose of.
Foams are only liquid adhesives for the first year or two of their existence. Foam outgasses (which is what makes it toxic in residential installations) which is also what causes it to disintegrate and lose structural integrity and adhesive/sealing properties. There are much better options for air sealing and insulation. I recommend Sega tapes and dense-pack cellulose.
@@lindacgrace2973 You mean Siga tapes, which tape foundation to wall?
🤦♂️🤦♂️. Just a lack of knowledge of options is all.
Could have done several things:
1. Exterior sealing (tyvak wrap with tapes).
2. Caulking spray the truss connections (air seals) and nail holes
3. Could have used drywall gasket caulking prior to drywall install to help the system.
Personally. Pro tip: if the walls/attics don't breathe...they rot. Mechanical venting is only half decent for long term functioning. Best to build the solution in physically
I think your analysis is way too confusing and way too complicated. The radiant barrier will still reflect some IR but the conductive heat is coming through is pretty much the same with or without the radiant barrier and that is what the foam will insulate against. The venting issue just is another (and effective) of getting rid of that conducted heat but the foam is going to insulate against most of that. The simple way to show this is just to mock up a sample and out a heat lamp on the roof side and measure the temperature on the inside. I suspect you will find minimal difference between foam with no gap and bats with gap. Also, one of the comments said you used open cell foam. I assume that is not the case, because that would not provide much insulation at all. As well, why all the hand wringing about vapor barrier. Most of the northern world has been using PE vapor barrier over fiberglass bats for decades with excellent results. Putting a new light in or missing a seal somewhere has minimal effect.
I was considering building this year, But I am Not willing to stick out my neck knowing what is going on in the world. And taking a chance with Sleepy Joe at wheel building materials have doubled price because of covid. It must b nice too spend money on using materials sponsored but still . Not digging but seriously hope that things change my job depends on election its scary because people are laying off for the 3rd time . I my just b stuck with just property if I don't have to sell ☹😟😡 seriously frustrated!!
I dont know anything about "your" job, but as contractors in this area are 6 to 8 months behind. I dont hear any talk about the election having a impact on their business.
Very confused on what you did in that ceiling
The way everyone else explains radiant barrier is exactly opposite of what you are saying. The way I hear it works is you need a space between roof and aluminum. Otherwise conduction will occur Thur to aluminum which is an excellent conductor of heat. So with aluminum on the face of your osb it will act as a conductor not as a reflector of radiation. So as far as I can tell can’t have both? Then you sprayed foamed on top of aluminum barrier and insulation will now act as a conductor considering it’s sprayed directly on aluminum with no space between. This should not be anything that hasn’t been well researched and documented. You a seem to act as if no one knows? I am sure this is not the case unless you trying to sell something which seems to be the case.
First mistake was never explained exactly how ceiling was made. Seemed to be in a big hurry. Slow down explain it carefully with drawings or diagrams. Be specific what you did.
Even that dog house experience was confusing in the other video.
I like your enthusiasm but slow down be careful explaining in detail.
Very important topic but too long and elusive. pls before doing content make preparing as for understandable pitching also building science issues
I hope Jordan you read this. Pls choose the content mission if it is too explain physics, radiant heat, conductivity you should give schemes and pictures. Or you are making content like Matt than give strict technology and than some explanation. So choose education or promotion content.
Dude, I would’ve rather her about how the spray foam gosh. It sounds like I’m listening to the view. Lol look I’m more interested in the best way to vent. So your exhaust fans work your bathroom and your kitchen and your laundry room like I said all as you talked about, was a bunch of gaggle women
I like your channel but May unsubscribe. You ask people to comment but you don’t give any feedback to the comments made??!!
Go watch Spray Jones on TH-cam! This is BS.
At the time I'm watching this there is a single down-vote. Who bets that was Risinger?
...
Just kidding people. I'm sure it wasn't him.
lol
Sreay foam is a garbage product that no one should use in a home ,