How Much Spray Foam Insulation do I need? | The most popular question answered
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- เผยแพร่เมื่อ 4 ก.พ. 2025
- This is a re-do of the June 2017 version of this video. Music removed and info updated and improved. Enjoy!
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Pulling up actual data really adds a lot of value to your channel. Thank you for this.
My pleasure!
How is it that a free 9 minute youtube video could have saved me thousands of dollars, days of labor, and headache with my local installer if I did 2 inches instead of 6 in my office build knowing this information. Hats off to you sir. Is there a way to donate to your channel? You will have literally saved me probably $15k or more on my current project I'm about to start. Thank you for sharing your wisdom and knowledge in these videos!
You need to ensure that whatever amount of SPF you place in will meet with local codes first.
@@SprayJones Agreed. My buildings are not subject to building insulation codes just my personal preference on thermal efficiency.
This is a great video. Really appreciate you putting it together. I was worried about "only" putting 3 inches of cc foam in my new build house. No longer. Thanks for clearing it up for me.
Thanks for great information.
I'm building a new garage this year and was going to spray the walls and blow in the attic. After watching your videos I will spray the complete garage now. It just makes sense.
I sprayed my house attic with 4 inches and expected to see the payoff in heat savings in 7 years. I was WRONG. Payoff happened in 4 years. I was worth every penny. Especially if you live in the far north of Ontario Canada. Love how it kept the rodents out also.
Sounds great!
Hey, how much did you pay to spray foam your Attic?
Great video.. me and my father often talk about diminishing returns.. this is great example of that.
Glad you enjoyed it!
Thank you! Finally someone explaining this in a simple way. You guys are amazing.
Thank you, glad to help that is what we want to do. Empower through educating.
Check out the other videos to complete your understanding.
Exactly.
@@SprayJones local company to me (Ontario) is quoting $2,500 tax incl for 950sqft basement at 2” thick. Walltite/CM01
Is this a fair price?
@@skyline5354 Yikes! That is super cheap. But I hear that about Ontario SPF guys they all like to give stuff away.
@@SprayJones Other trades too. Brand new 2k sqft home here is wired for under 5k all in. I won't work in Ontario anymore.
Common sense derived on facts. Awesome job presenting info in all perspectives!
Glad it was helpful!
just had 3 inch closed sprayed on the bottom of the roof deck and 2 inch in the walls. the change is unbelievable. im sold on it when i get to renovating the rest of the outer walls i will def have it sprayed
Glad it worked out. Thank you for the testimony.
Thanks for the great information!!! Just had a guy tell me I needed 6 inches on the roof of my steel building! With this information I will go with 3 inches! And go with a different company! Wish you guys where in Arizona!
Glad I could help!
I see you respond to soo many comments. I am in Zone 3 (atlanta ga) and some installers are saying do 3 inches and some are saying 4 inches of closed cell on a new build. The 2 that are saying do 4 inches are saying it will encapsulate the roof truss and reduce thermal bridging. Just not sure which to do.
I like the 4" for those reasons. A 3.5" top cord allows for 4" to go over it nice. We never build a ridge of SPF directly over the cord, instead just allow the SPF to crest over it and keep it imbedded.
I live in SW CO and our county has no code enforcement. I am taking advantage of this to keep my foam costs down. Our house is ICF construction, and I had 2" of 2lb closed cell sprayed on the underside of the shed style roof that extends over a three room bump out on the first level, making the attic of this section conditioned space. In the winter, it stayed "room temp" above the ceiling. This summer, I do see that it is getting warmer, but not enough to be a concern. (Room temp ~75F, attic ~80F, 95F outside in full sun for days, no A/C) Thermal imaging shows that most of this heat comes in through the trusses, not the foam between them. I am going to opt for 2.5" on the main roof, which is rafter style vaulted ceiling using TJI's. Thanks to the TJI's, I should have much less thermal bridging, and 2.5" of foam should keep pretty much all the heat out in the summer. I already know 2" is more than sufficient in the winter. With 2 to 2.5" of closed cell foam, my house is technically WAY under the R-value of most codes, and yet the performance of my conditioned envelope is likely better than I could have achieved with the use of fiber insulation of any kind, particularly considering my TJI rafter vaulted ceiling design, which would be a pain to vent and insulate properly. Very happy with spray foam, we really need codes to start allowing less of it to be used rather than demanding an r-value...
Chris Grider:
How are you venting that attic space?? I didn't see any baffles before spraying, how does excess moisture escape? How do you know if you have a roof leak? Would this cause the roof sheeting to rot?
SPF attics do not need to be vented. Watch the 4 part series on non vented roofs to learn more.
Great video. Question: My rafters are 2 x 10. If I spray 3" then what happens with the remaining 6.5" of cavity space? Wouldn't condensation be an issue between the drywall and the closed cell foam? If I place batt insulation in the remaining cavity wouldn't that also be susceptible to condensation?
No there will not be condensation. The cavity is deep than needed, you have to renew your mind to how well SPF works.
No air through the foam, you are buying a shot of whiskey not a pint of beer.
I disagree with the numbers converted to percentage, because it's based off of 0% efficiency being a loss of 558btu/hr. So when you compare that to how much do you save using 3 inches and more vs 2 inches it don't sound like much as a percentage. But when you do the math on BTU's for an actual structure square footage you end up with some big differences. I did some quick math here, 40x72x14 4:12 has about 6624sqft before windows and doors. 2 inches requires 21,358 BTU/hr, 3 inches 15,951 BTU/hr, 4 inches 12,977 BTU/hr, 5 inches 10,273 BTU/hr. So 3 inches is 33% more efficient than 2 inches, 4 inches is 65% more efficient than 2 inches, and 5 inches is 108% more efficient than 2 inches. This should be what the numbers are compared to. And the efficiency comparison in the video doesn't do these real numbers any justice.
I started doing the math and came to the same conclusion.
Really glad you put this information out. Thanks for taking your time to do this.
Glad it was helpful!
This is great information. Would the same percentages in your chart be the same for a ceiling?
Thank you , brother for your advice and knowledge
Thank you for your helpful and practical commentary about how much spray foam insulation is necessary. My builder in New Mexico is only willing to use open cell. Can I extrapolate from your data that if 2 inches is the sweet spot for closed cell, it would be 4 inches for open cell. I am in southern New Mexico (climate zone 3) and so it doesn't get as hot as Phoenix nor as cold as Minnesota and so I would hate to go overboard with spray foam insulation if the value isn't there.
My personal beliefs is a mixture of closed cell with rock wool insulation laying over.
Closed cell gives you structural integrity, air and moisture barrier properties and great insulation values. While the rock wool will give you great insulation values as well for what it is, but I am looking for the amazing sound qualities it offers. A 2x6 wall with approximately 2 inches across the entire house (closed cell) and then filled with 2x4 rock wool. While having 24 inch center stud walls.
Rockwool needs ventilation won't work with foam
@@dillonbledsoe7680 ??? What???
How do you get that? If it’s in a closed wall as all homes are then how is it code compliant?
The thing you have to watch out for is mold growth. I'm going through that right now. If you have a closed cell and then any type of bat insulation it is really difficult to get the bat insulation without any gap between the spray foam. That dead airspace can create mold in a cold environment.
@@snapcrack55 … that’s true… I decided to just use rock wool in my studded walls with two overlapping layers of closed cell boards with reflective aluminum foil attached on the outside exterior walls. House rapped first, foam boards, 3/4” gap for reflective material and then roofing metal to finish it off. Looks just like a farmhouse.
Thank you for being honest and saving money
I did 7 & 8" of closed cell on the roof deck. Percentages are deceiving. So in my case 3000sq./ft That's about 3700BTU's of heat per hour which is about 10M BTU's per season. This enabled me to downsize the overall heating system nearly paying for the upgrade Plus the savings every year.
Good info. When I'm ready to build in 5 or so years i plan on 2x6 framing, or bigger, 2in closed cell and then rockwool, and exterior insulation for thermal break. Going for a passive house rating in northern MI.
Ok
2-3 inches is all you would need, dont spend the extra on inferior insulation.
The Rockwool would help reduce sound the transfers through the closed cell foam if you are in a noisy area. You do get thermal bridging through the studs yet so exterior insulation is a good plan if it breaths like the Rockwool product. 2 inches isn’t enough by itself. You will see a substantial difference through a thermal imaging camera from 2-3 inches. I usually recommend 3 sometimes 4 inches and being done with it unless it’s in a noisy environment. Then there are other requirements needing to be met. I’ve even done a handful of 5 inch applications on roofs over the years. Back when foam was cheap anyway. Now it’s about double the price from 1.5 years ago.
Another great video -- Thanks for your knowledge share!
Glad it was helpful!
Thank you !!
I agree with everything you said! Only way to justifie more foam is if energy cost rise drastically then it may start to make sense but then most likely the foam will cost more too.
Yup.
@O P no, chemical is a big cost most instance it’s the bigger part of the job it used to be 50/50 Labour/chemical. Example i sprayed my shop 36x50x16 2“ walls and ceiling I was ablte to heat it with a wood stove to about 8c with a Osburn 3300 Woodstove only at -30c Manitoba. I added 2“ to a total of 4“ so I can heat it Easier plus I’m a contractor so I do it myself. If I where to hire a contractor I’d say do 3“ ceiling 2-3“walls I think best Bank for the buck as far as the efficiency I feel I need. Now as we see hydro prices sky rocket and Insulation materials I’d consider going more as much as you can as it’s just a matter of time it will pay for itself
2 things you can count on going up for your entire life is energy costs and taxes.
Using data is so powerful. It’s so rare these days to actually find an answer to a question based on science and not “trust me bro” opinions
Watched more, love the detail on heat loss and spray foam efficiency!! Good job
Glad you liked it!
I finally found what I have been looking for. Thanks!
Glad I could help!
👍
Is there a threat of condensation on the drywall back if a cavity is not filled
No
Great video...Top shelf information. Thanks.
Thanks for watching!
This was very helpful. I have a 12×20 cabin with 2×6 walls. I have a wood stove for heat and winter cooking. Completely off grid (no electricity). I have been hesitant about spraying, just because I really didn't know how much, really how little I needed to be efficient with my wood burning. I believe, according to your explanation, that I really only need the 2" level of spray. I'm using plank walls, so there is a going to be an air gap between the spray and interior wall. Should I still put a vapor barrier behind the wall boards, or is that overkill?
Honestly watch more of the vids. All these questions are answered here including the vapor barrier one.
I would say "no" as the spray foam give you both a thermal break and an air break, per Mike Holmes on his show. Spraying 2" of foam also means you are not burying your electrical wires in the foam. You can have the wires proud of the foam, for the most part, which makes any remodeling down the road a lot easier. Even if you are off-grid, who is to say you won't want to throw up a solar panel and a couple batteries and at least have some LED lights?
Thanks for the infor. You indicated that the insulative value of the closed cell is much higher initially and reduces with time. So how old is the spray foam for this c-236 test?
That would be valid for discussing the LTTR value - in fact we want to know how the performance is and that is good from moment one.
For instance a house insulated today is not 10% worse within 3 months as far as performance is concerned.
However the white-paper values of lab tests would differ for one aspect of the that test.
There’s some proper application, multi pass, staying off the studs!! Good job boys!!
Thanks
Wow, thanks, very educational and informing, thanks, stay blessed
My pleasure
Do you have comparable efficiency charts to compare “reduction in heat loss” compared to fiberglass and other common insulation types?
So nice! You do excellent work -- QUESTION -- We love the look of concrete, especially in the cottage we are planning, an exposed concrete wall in the basement. Can we spray on the exterior (below grade), with enough insulation to keep the interior surface of the concrete at room temperture during winter (3 inches??)? We want to see the interior concrete but we don't want a huge cold surface during winter. Temperture can hit -25 C during the worst of winter.
Please watch the videos in the playlist "in contact with ground" to bring you up to speed.
What’s a better option doing 3 inch spray foam or doing 2” with 1 1/2 batts im trying to get good r value but also help with acoustics as I live on busy street. Same question goes for ceiling in basement should I do batts, open cell foam, or both basement ceiling is strictly for acoustics, and what do you suggest in attic ceiling because I hear blow in drops down to r4 in -25. Great video btw
Great information
Very good explanation. Accuracy matters!
Glad it was helpful!
Hello, great video as you explain thoroughly, I have a question have you ever sprayed closed cell in an area and then sprayed open cell on top of closed cell as that would fill full 2x6 wall but it may be an experiment to make a video on.
We do not do that. Yes a video needs to be done about that for sure. So subscribe and watch it will be coming out.
I love the BTU retention charts. Do you have the equivalent charts for any other types of insulation? I'd be curious to see how they compare head to head in this test, seeing how the r-value test is tilted so heavily in their favor.
Go watch the R value Myth video...
How is spray foam thickness measured? Is it like 2 inches equals inch and a half as in you would measure lumber or should it be 2 inches equals 2 inches?
Measured with a probe. Nominal thickness is 1/4" low to 1/4" high.
I have watched many of your videos. Spray Foam is where it's at! Great information. But - how does one put it into practical use? I am building a small, 1000 sq, modified cape in southern MA. Code requires (ZONE 5) an R 30 wall value. How do I convince a building inspector that I only need 2 inches of closed cell? Ceiling are an R60!!!! I'm not sure what a cathedral ceiling requires but that's what we're constructing..
You cannot. You need to have a consultant write your specs that has the ability to seal the design.
Your videos make me want to start a spray foam business. Thank you for the amazing content!!
Beware, that has been tried only to be followed with much regret...
But I get what you are saying, inspiration is found in excellence.
Great content...as always. Thank you Mike!
For spray thickness..what about a wine cellar? Would it be worth those few extra percentages to fill the entire cavity of 2x4 and 2x6 wall? Should closed cell be used for a wine cellar?
All the data applies for Vino.
@@SprayJones OK. Closed or open celll?
@@velocityacoustics Spray Jones will ALWAYS go with closed cell if there is a choice. It has all the benefits: very high insulation value, moisture barrier, rigid. The open cell is no moisture barrier until it get a certain thickness and that is not keeping the moisture out. It is just holding it in the spaces between the little balls. And not nearly as rigid.
This is VERY helpful. If I'm in northern Wisconsin and want to insulate my attic floor how many inches of closed cell foam + insulation would you recommend? Or would you go with 2 inches of closed cell and call it a day?
You better watch the spraying down to drywall video first. It is in the vaulted roof playlist.
The latest energy codes (IECC) just implemented in the USA require a substantial R-value requiring a full 2x6 cavity of closed cell foam for residential construction if you want to avoid paying for continuous exterior insulation as well. Most will probably go with the full cavity of spray foam because of cost. Most will not realize the benefit of preventing thermal bridging with continuous exterior insulation and reducing the amount of cavity wall R-value.
Would it make a difference if you put an air space between the first two inches and a second two inches of spray foam
No.
thank you for all the info. great videos. question. i am adding a shed roof 4 season room to the side of my house. It will be built off the ground on cement piers. since the floor deck will only be 1 foot from ground, to seal the bottom of the floor, i plan to install cdx treated plywood between the floor joists . The 4/12 shed roof will sit on the current home shingled roof . Since it will be a cathedral roof. concern is proper ventalation. i was planning on useing fiberglass bats, but after watching your videos thinking i should use closed cell in the entire room.
Combining old with new can be tricky. You need to have enough room to spray the foam, that is #1. Then you have to divide the two so that cold vented roof will not affect the SPF section.
You've touched on this before that it can be a big problem if you can't get to the space needing foam .I totally agree you could indeed miss important structure that needs to be sprayed to complete the seal and that is so important. But here's my question how would you do it with any other products it's even more impossible to properly seal so I'm thinking is you can't foam it likely you cant do anything else either
Hello, love your content. Quick question…what causes ridge rot? A local high end builder at my church says to put in a ridge vent and space down between rafters and then seal it all off with spray foam. This allows moisture to be pushed up to the ridge and out without affecting the air barrier. Thoughts?
You are mixing up insulating methods. Ridge rot is something to do with humid attics that have ventilation problems.
SPF uses a non-vented attic. Watch the 4 part series on non-vented roof. I have a dedicated playlist for the vaulted ceilings and SPF.
@@SprayJones thanks for replying. I was just told by a local contractor to be careful when going to SPF due to new found cases of ridge rot when sealing up an attic, or in my case the second floor rafters. My research disagreed and that is why I came to you for an answer. I will rewatch that series of videos. Gotta make sure this is done right. Thanks again.
Question, for the additional inches above 2 inches, don’t you need to stop and allow the first 2 inches to cure to prevent offgassing going on for all eternity by applying it to thickly? Thus you now have an additional labor cost as well as an additional material cost.
Yes. But the chemistry is changing to allow for 4 & 5 inches in 1 pass.
Watch tomorrow's Toxic SPF video to learn more about your question.
Well that’s good because some hack installers have made people’s homes unlivable in years past by globing it on.
Love your videos. I've learned a lot. The information will definitely be helpful when building my soon to be next home. Thank you from the lower 48.
Awesome! Thank you!
4 part series coming out next week on Roofs and SPF. Everything you want to know and maybe more.
At theses lumber prices?
I was thinking about offering a guy a sheet of 3/4" plywood and 4 2x4s for his Harley.
Idk, I might be getting ripped off..
Good information
Thanks
Thanks Mr @SprayJones! Why do some areas like mine (Nova Scotia) ask for r24 value in the walls (5 inches of foam) when an r13 of foam will do? Should a homeowner build to code?
Code is written for fibrous, but at this time there is no designation for batts vs SPF on white paper. Unless you are not having new code enforced.... then you can do what physics and your wallet says.
Gosh I just love your videos. Well done! Clear delivery of info!
Glad you like them!
Bravo! Just finished a deep dive of your vids. We will be using ccSPF in our home. Insulator quoted 3" for code R-21 on the Rims, Walls, and Roof. Question about the roof foam; can we put rockwool in the bays after the foam (Flash and batt I think it's called) to get a better result?
No!
Watch the flash and batt videos. You do not need it once the foam is there.
We're going through that issue right now. We had an inch and a half spray foam on our vaulted ceiling and then fiberglass bats over that. The problem is you can't get the fiberglass tight enough to the spray foam and then you get mold growth in that dead air space
Thank you so much for all that data... data-data ..data-ta data.....Sprayfoam man to the Rvalue rescue!!! (Sorry it's late and I've been watching spray foam videos for a couple hours.
I've been building for quite some time, and expanding in some ways like ICF variations - and I'm looking into spray foam.
The current remodel i'm thinking of using it on is a home built in the 1950s. I'm thinking of vaulting the existing ceilings, the roof is a low pitch, it's in So Cal so it doesn't need a steep one for snow and ice. The rafters are 2x4s, which have no depth - so this will work great, I am still not sure of at 2 - 2.5" thick what will the "R-value" be?
Any tips are welcome. 😁👍
That being said, what will the weight be like, say in a standard 16" o/c chamber wide 10'x10' area?
I'm not sure how to calculate that or present it to an engineer, unless they are familiar with doing roofs with the spray foam.
Would the 2x4's need to be beefed up / sistered on - with a 2x6?
🤔🤔 - totally open to thoughts / ideas?
And great video. Seriously thanks for the specs and another person giving info on TH-cam spoke of you and how you are one of the 'Obi-Wans' of spray foam.... Keep it up, the Grasshoppers are listening. 😁😂😆.... (I warned its late....)
Closed cell SPF weighs 2lbs per cubic foot or .166 lbs per board foot. A board foot is 12" x 12" x 1".
@@SprayJones hello there. 👍
Thank you so much for the response. Ok so just under 2lbs. 🤔
Interesting. I’ll have to give some thought to sistering on 2x6s for some added strength. Just for long term peace of mind. And it will add further space from the foam to the drywall so no shaving, and a gap for an insulation barrier….
🤔
Again thanks for the info and the good videos. I’m thinking of using the ‘Froth-Pak’. There just doesn’t seem to be companies in my area offering it. I talked to a manufacture rep in AZ a month ago and he was going to send my info to a couple companies…. An hour away, over a month ago. I think they passed 🤔😆
Have a good one sir. 👍👍
@@Jonacarpenter Froth paks are hard to get right for large jobs. You really need a pro. Keep looking you should be able to find them. 1 hour away is not that bad we travel that all the time.
Do this right, once or not at all.
@@SprayJones oh I agree with you. I’ve been a GC for over 20 years. I haven’t ruled out hiring a sub. And I haven’t finished my investigating / learning all I can. And it’s a small job, not the whole house. That’s why that pack caught my eye. And one of the videos on it was quite detailed. I’m still searching. 😉👍
My question is what thickness of 2 lb closed cell spray foam gives you a vapor barrier on inside walls? I want to flash and batt with rock wool. How much CC foam will I need to put on the rim joists to ensure that water vapor that moves through the rock wool will not condense on the inside surface of the foam in winter time? Obviously the foam has to be thick enough to lower the dewpoint at the inside surface so vapor does not condense.
I have 24 foot high ceilings in my shop and the walls are built 90" on center 6x6 beams. The added bonus i could see with having thicker spray foam walls is better shear force when its windy.
You get a tremendous amount of shear force out of 3 inches of closed cell already. Your building is never going to fail from shear forces at 3 inches so why go over that?
Agreed.
How much sound deadening Do you achieve the thicker you go? Any published calculations?
No data on closed cell. Open has that.
Very helpful video. Do you have a link to the source for the chart? That would be very helpful.
If you have closed cell foam installed on your attic roof and later get new shingles installed, what can be done with all the new nails? Sometimes the nails they use are way too long. This could extend through the foam or decrease the insulation value. What can/should be done with new shingles if you have solid foam?
If you have already answered this I apologize for the same question. I haven't gone through all of the comments yet.
Very informative videos. Thanks.
This is really important for the 2nd floor ceiling, (no real attic just the space from the 2x6, 2x8, 2x10 or whatever is used for your roof) . How can you fix this without removing the drywall? Thanks.
Don't be an idiot and install the Wrong thing!
Just install the shingles. We have had home loose shingles in wind storms and they just put them on.
Question: What do you do about all the new nail holes in the sheathing?
Watching this video again why at 6:50 is there piece of poly there like if you were insulating with fibreglass and having a continuous vapour barrier?
Jobs are switched over from batt to SPF.
Does the application of closed cell spray foam ever melt wires? What temperature does the foam normally reach when it’s first applied and curing? My builder is putting spray foam in our remodeled house and I’m concerned it will melt cables, but I heard that’s pretty unlikely
Foam will not melt wires if: you have good quality wiring, the foam is installed according to the design parameters.
@@SprayJones Thank you!
Question: Any Idea if double walled 2x4 construction, with a minimal foam thickness (say 1inch in the inside wall and 1” on the outer wall) separated buy an air gap of ( 2.5” between layers) would deliver better insulation results than a single layer of 2” thickness?
Too hard to say.
Construction needs to be practical for whatever solution we bring.
@@SprayJones double wall construction is being heavily promoted. All over YT, but never using foam for insulation.
@@4pharaoh Oh, yah.
Well let's see if I can come up with some mind blowing data soon for studs.
What about roof leaks if you have spray foam on attic ceiling?
Hello there, what kind of product do you use and what are the temperatures that your guys normally use?
The product is Walltite by BASF sold in Canada.
The rest I can't tell you..... Goldilocks!
Do they have that same test for open cell versus closed cell?
Hey Mr Jones thank you for the great information! What are your suggestions for my roof if you dont mind? I'm in southeast Georgia, zone 2 i think.
- ICF walls with a 6" metal stud roof.
I was planning for 6" of closed cell but now thinking maybe just 3" or 4". What do you think? I dont think i will have a thermal bridging problem since the metal studs are so thin and dont have the 1.5" mass that would block foam.
Any help appreciated!
What is code for your area? Do you have a white paper value to hit? 3-4" is at diminishing return for closed cell as I said in this video. Steel studs love spray foam - just have to spray it sensibly so the rising foam doesn't push them all out alignment - but that is easy to figure out.
R-25 for zone 2 roof insulation. I have cold rolled steel every 4' in the studs and will have hat channel every 16" run perpendicular to the studs for the drywall attachment, so movement of the steel should be minimal. Thank you for your help sir.
@ Join my new platform launching soon. It is what these kinds of questions are all about.
Education, community and Q& A access.
Question. Is there an advantage to 1" of closed cell followed with 3" of open cell? As opposed to only 2" of closed cell? Some installers are recommending this application mainly due to cost of material. THANKS!
Pick one product.
Nice video, I was planning to install an r20 on my basement walls, but now I feel comfortable with r12. I have an attached garage with 2 bedrooms on top of that, my contractor told me that he can spray 5" over the garage drywall, but it would be better to tear down and spray on the garage ceiling, does it make sense? Right now I have an r20 pink insulation, I will have to install new drywall on top of the spray foam.
What about allergic reactions if the contractor doesn't mix it correctly.
I know today there is no formaldehyde in the new stuff
I have watched 60 minutes where people in Georgia had to remove there entire roofs because the foam making them all sick.
Is the stuff that's at the home depot in 2 cylinders safe I think its from tiger ?
Go check out the health and safety playlist. Your questions are answered in there.
Sub, I have a video dropping next week that will answer stinking foam right off at the beginning.
You should definitely check out more of these videos. For some reason I was thinking that the reason it was making people sick was because the used open cell against the roof and it drew moisture. When this happens mold is a very bad issue. Closed cell won't absorb water because there are no "open air cells" for water to permeate.
Great video. My only question as I have seen your video on the roof and closed cell. I am in TN in the USA. As the architect plan on your closed cell foam roof plan specified 4" inches under the deck. Would you suggest that as well? I plan on doing 2" under my slab, 2" on the walls, 2" on my ceiling under my conditioned attic space. But am confused on how thick I should go on the roof deck, which will be zip, shark skin and then shingles. Not really sure. I am not really under any code or forced codes at this time. So just looking for some solid advice on what you would suggest in that scenario in this instant. As I do not have to conform to any codes or restriction. I mean will 2" be good on roof deck or should I request more? Thanks
3" or 4" will be fine if compliant with you regs.
Is there a risk of mold forming on the drywall if there is a gap to the outside sheathing
No
Yes 😂 we have to spray 7" of sprayfoam for ceilings/roofs in Virginia. I tell people you have a yeti cooler by the time we are done. Our estimates are in the 40k range because of the requirements of "R-value"
That needs changing.
@@SprayJones yes it would cut costs significantly. To bad the fiberglass manufacturers got the market cornered
I have 2x4 framing on my basement walls, does it make sense to remove the framing before applying the insulation? I am concerned that there is not enough space to install 2" of spray foam behind the studs, in some places I only have a 1" gap between the wall and stud.
Leave it. Not worth the messing around for the inch. Have done lots like that no one moves them out.
@@SprayJones thanks for the answer
@@brunomourasilva6247 the 1 inch gap is great. It gives you a thermal and moisture break from the concrete wall and studs.
Thanks for this video....should help us optimize the investment in thermal protection. One question still....what is the minimum waiting time between layers? The company I'm considering to contract for such a job, is using close cell PU foam from Huntsman (DALTOTHERM® TSA30-00), and in the technical specification sheet, it says that for more than 12cm foam, there should be a 12 hours waiting time between the layers, but it doesn't specify what should be the waiting time for less than 12cm. I was considering to apply 15cm of foam, but still in one day. Many thanks in advance.
The answer is "I don't know". Because I would consult the data sheet, or call the rep.
We use Demilec and it can take 100mm (4 inches) in 2 passes with no waiting between them.
The technology in the chemistry is rapidly changing and improving, so you have to ask those who make it.
@@SprayJones thanks. This one can take up to 40mm per pass. I will try to get a feedback from the manufacturer
@@MrSavage77 Maybe a typo? 40mm = a little over 15 inches. but 4 mm = 1.5 inches.
I'm in Laredo, TX, high heat, humidity, I'm considering switching from my current build plan of open cell to closed cell. Would you think that's a better option? Spraying the attic space under a metal roof and the walls. Interior walls would be open cell just for noise.
Thanks and I appreciate all of the information you've shared with us.
2 lb foam is the king, has been and always will be. That is 99% of what we do.
Get it installed correct and you will have it for generations.
In Texas where you have your vapor barrier on the exterior of the building and dry to the inside, open cell is king. It’s cheaper and you can pile it on to stop heat flow.
This video is great!
One question: Can a person spray foam the roof on an attic that is vented and unconditioned. Would that 2” inch or so of foam act as (or replace) a “Radiant Barrier”? (The radiant barrier being that think aluminum foil looking stuff).
Better watch the video on going into an enclosed attic to spray. You can find it in the "how not to get cheated" playlist. It is called spraying down onto drywall, should this be done.
I am planning to insulate my basement walls with spray foam, but I have huge stairs in of the walls, making it hard to insulate the area and rim joints, will that influence my air seal and insulation performance? I can only insulate on 3/1-2 walls.
I usually do 2 inches on concrete and 3 inches in the rim joist. You won’t be able to spray behind the stairs if you have finished Sheetrock already on there. While it’s best to have it all done, it won’t make a substantial difference if it’s just a really small area.
What would be the point of 2x6 framing if you only spray 2"? may as well build with 2x4s?
Correct.
@@SprayJones I can frame 24" OC with 2x6, that would increase the coverage of the foam and decrease thermal bridging, right? With 2x4s, I would have to frame 16" OC
@@ThePotatusMan Thermal bridging with wood studs is no where near what ppl think it is. I plan to do a test shack to prove this.
@@SprayJones Love your videos. Did you ever do the test shack? You have so many videos, not sure what it may be called. Thanks
How well does this keep the sun’s heat from penetrating a cathedral ceiling? My spray foam contractor recommended 3.5”.
Fine. I have no objections to that.
Very useful info thanks
Glad it was helpful!
Do you have info like this for open cell? We are about to start building here in Arizona and the sub uses open cell down here. Curious if we are making the right decisions on what we are doing.
Open cell does not seal the house or or stop water vapor only close cell does that.
Close cell also does a better job of insulating with the least amount of foam.
I hope this helps.
@@scruffy6151 Why would open be recommended in a hot dry climate over closed? We average about 80 days a year over 100 degrees F.
I do not at this time. I would have to look around for other sources to see. 2 lb is so prevalent that it gets all the old school tests.
Open cell is a cost thing. Where no structural support is needed nor a vapour barrier why pay more? It really is a marketing item.
I am going to do a video on why open cell was developed and how / why it became popular.
@@SprayJones So in Arizona would we be ok with open, or should I be talking to my contractor about looking at closed cell?
Hey mike
Great video… i just had my home sprayed from the exterior and the contractor that did the work sprayed closed cell 2lb 3 inches thick.. it looked like they were doing it in 2 passes. However I do have a question.
In areas where they sprayed too much they had to shave off areas and the foam on the inside is a different colour and not purple it also has little bubbles almost like thousands of little air pocket bubbles… comparable to a chocolate aero bar but smaller pockets… it feels dense but not as super dense as the foam shell on the outside is this normal?
Normal. Is there any issues with your insulation ?
I live in Florida and looking for the code for closed cell spray foam
Is 6.5 inches (closed-cell) on the under side of the roof deck too much in Maryland?
I don't know your codes.
@@SprayJones Old codes were R-38 minimum, new 2022 codes are asking for R-49. However, anything above 7 inches is an automatic jump to 12+ per sf (the next level or tier), while the 6 inch tier is around 8 per sf according to my spray company. My roof deck is 3195 sf.
@@vince2007combustion What about for vaulted ceilings? Less than that?
@Spray Jones Yes, R-38 or 5.5 inches minimum for sloped attic ceiling... I increased the thickness to 6.5 inches due to the 2x6 (5.5" width) top chords in the trusses. I was concerned about thermal bridging by the exposed edges of the top chords. By increasing to 6.5 inches, the edges are covered by 1 inch of closed cell. The gable walls are 3.5 inches thick (also closed cell). At a cost of approximately $6,000 more, will the extra inch make a difference, or is it unnecessary?
How do you get from the data at 2:47 to the data at 3:03? If I use 24.5 ft2 and 72 deg dt and the heat flow in the table, I get an R value of almost 12 per inch but the data at 3:03 shows a value of 6.
You are cross referencing two things: First is the heat flow of the test, the second is relating that back to an ASTM test for resistance value in a lab test for "R value"
It proves that the Lab test for "R value" is still way off in real world conditions.
Hence why I do no like to even us those numbers when talking to people. But we have been saddled with this myth.
Not to mention the air seal with spray foam not achieved with fiberglass or rockwool insulation and some people will argue that a plastic sheet will achieve that, which it will not.
After you spray 1" of closed cell foam , how much does it expand ?
Under ideal conditions expansion for 2 lb foam is x25 the liquid mass.
How do we get those that are doing plan reviews to get away from R-Values and to thermal efficiency?
With much planning and tactical clout. This is a rigged game against us.
Do you have any data for sound resistance for closed and open cell foam
Open cell yes. Quite a lot actually. None for closed cell. No one tests closed cell for sound, it is a thermal insulation first and foremost.
@@SprayJones i thought closed cell would be the go to because its so dense
@@mrsoccergod5001 Less dense takes more sound waves out. You need air tight and then light and fluffy. Think of sound mat in a recording studio, light and squishy.
Question how do we deal with local building codes?
With high-powered help.
To get the proper R-value in my attic can I spray 3 inches of closed cell and then spray open cell over it to get the R-value needed and save on cost? We want to make this a hot roof that is why I want the closed cell sprayed directly on the roof deck. Thanks
You are off in the weeds. Watch the 4 part series on roofs and SPF. All your questions are answered in parts 1-3.
@@SprayJones The problem we are having is our local code won't let us spray just 4" of foam. They say it doesn't meet there codes. I know it exceeded them but try telling them that. I just want to do the hot roof but I can't afford the amount of closed cell it would take to meet there codes. That's why I was wondering if it was possible to do what I asked? Thanks for your time
@@ronaldmoubray2527 What is your code R value for a vaulted ceiling?
@@SprayJones r-24
There you go. You install closed cell to the roof deck cathedralized attic detail to the R24 and all is well. 100mm of SPF should do it.
Have it drawn and sealed by a building envelope engineer if you need to like I have been saying and showing in all the 4 part series on roofs. The info is there open source.
good day, I have watched many videos about spray insulation, but all insulate only the interior. My question : 1. can the insulating foam also be applied to the exterior wall and can then be plastered over ., or covered with Fibercement Board. 2. are Hollow Blocks can be filled with it and then results in insulation. thanks
Yes, but exterior insulation is more difficult and requires extra steps to be taken to support the finishing system that will hang just in front of the SPF.
It is truly the best way to go and is done commercially a lot.
@@SprayJones thank you, but that was not my question , and then how is the instalation of the polyurethane foam ??
Good work, you guys seem very knowledgeable. With so many fly by nighters and cowboys out there do you happen to have any referrals for a spray company in Ontario, I’m looking to do my attic.
Talk with BASF in Toronto and they will get you in touch with certified people around you.
@@SprayJones thx
Can you use a layer of open cell foam on top of closed cell foam?
Yes.
I thought it was against the law to use freon and spray it into the atmosphere as it ruins the ozone layer ...........please advise .......
Good day
Just wondering what brand you would recommend to a first timer doing this in Canada's far north I want to do a 2" spray and I am looking at using FROTH-PAK FROTH-PAK 620 Sealant Foam Insulation
Froth Paks are a disaster, not to mention illegal in Canada when not used according to their limited certification. You need a professional contractor spray foam that meets the ULC requirements set out by code.