Home & Garden

Ask me anything about spray foam insulation

  • Last Updated:
  • Jan 27th, 2024 9:34 pm
Deal Addict
User avatar
Nov 15, 2005
4549 posts
2623 upvotes
Are you able to spray into existing dry wall without tearing it down? A couple of rooms are pretty cold because of the exterior walls and I would rather not tear down existing walls to re-insulate
Deal Expert
User avatar
Aug 2, 2010
15196 posts
5016 upvotes
Here 'n There
Great thread. 3 questions:

1. A friend of mine had his place spray foamed and he ended up with spray particles on the faces of the studs and he had to scrape it all off before the drywall went on. The installer said it wasn't their responsibility. I guess it should've been in the contract that the studs would not have any foam on them or be scraped by the installer. But then I saw on episode of This Old House and they sprayed some kind of oil on the face of the studs before they started foaming so any foam that got on them wouldn't stick. How do you avoid getting foam on the studs or what do you do if it ends up there by accident? Whose responsibility is it to remove it if it ends up on the face of the studs?

2. There seems to be conflicting information about whether in Ontario there needs to be a vapour barrier put on top of 2 pound foam or not (you know, that plastic sheeting). Some inspectors say yes and some say no and I'm not sure that the Ontario Building Code even speaks about this with respect to foam insulation. My concern would be if any moisture does get behind the plastic sheeting it would be trapped in between the plastic sheeting and the foam insulation.

3. I heard that foam insulation shrinks very slightly over the years and away from the studs and therefore is eventually not a perfect vapour barrier. Is this true?
Jr. Member
User avatar
Feb 3, 2014
187 posts
77 upvotes
Mississauga
boonjaca wrote: Are you able to spray into existing dry wall without tearing it down? A couple of rooms are pretty cold because of the exterior walls and I would rather not tear down existing walls to re-insulate
The only way to do it is the "drill and fill" process where holes are drilled into the drywall and foam is applied into the cavities behind them. I personally don’t recommend this method because without seeing where you are spraying you cannot be sure how accurate the job is, but if you have no other options it’s the only way to go.
eonibm wrote: Great thread. 3 questions:

1. A friend of mine had his place spray foamed and he ended up with spray particles on the faces of the studs and he had to scrape it all off before the drywall went on. The installer said it wasn't their responsibility. I guess it should've been in the contract that the studs would not have any foam on them or be scraped by the installer. But then I saw on episode of This Old House and they sprayed some kind of oil on the face of the studs before they started foaming so any foam that got on them wouldn't stick. How do you avoid getting foam on the studs or what do you do if it ends up there by accident? Whose responsibility is it to remove it if it ends up on the face of the studs?

2. There seems to be conflicting information about whether in Ontario there needs to be a vapour barrier put on top of 2 pound foam or not (you know, that plastic sheeting). Some inspectors say yes and some say no and I'm not sure that the Ontario Building Code even speaks about this with respect to foam insulation. My concern would be if any moisture does get behind the plastic sheeting it would be trapped in between the plastic sheeting and the foam insulation.

3. I heard that foam insulation shrinks very slightly over the years and away from the studs and therefore is eventually not a perfect vapour barrier. Is this true?
1. A good installer would normally take care of that himself. What size of particles are we talking about? If they are specs no bigger then a 1/8" I would not be concerned since very few walls are true. If you shine a laser along the 2x4 stud faces along the wall you would see it’s never perfect. Also small specs would get compressed when the drywall gets screwed in. Personally I run a scraper along each stud face after a job to clean it up and it only takes about 20 mins to do on an average size job. I’m not a fan of the oil approach since it will react with the foam slightly. Some installer use tape on the studs when it is a retrofit and the owner failed to remove all old nails and screws. The tape takes longer to apply but is easier to remove. There is no set rules on who does the clean up but if you pick the right contractor then I believe they should take care of it. All of my jobs I mention that we do the prep and clean up of site.

2. It all depends on who’s reading the code book. Some people think that poly tarp 6 mil is another name for vapour barrier (vapour barrier = vapour permeance of less then 60ng/Pa*s*square meter). Foam exceeds that. Having said that, it all depends on how the foam is installed; whether it’s monolithic and has no thermal breaks. As the code book states, yes you need a vapour barrier, but what good will it do to trap air in between foam and plastic? This is why most educated building officials are passing without it, though there is no guarantee that they will. In the last five years only 3 of my jobs were required to have it installed. I do not install 6mil poly and always mention this to clients as a liability.

3. When installed properly the foam should only reduce in size in the first few hours while it is cooling. Normally the inside temperature of foam that is just sprayed is about 220F in a 2" thick pass. After it has cooled it will not shrink. If you have someone who blasts the foam very thick and hot then you may end up with unstable foam. It cures while being too hot and then is under constant tension. Again this comes back to people looking for a deal. And yes if it separates then you lose not only the vapour barrier but also the whole point of using spray foam. Once again, it comes down to being careful who you choose to do the work.

--
Peter
Owner, VIPFoam.com
Deal Expert
User avatar
Aug 2, 2010
15196 posts
5016 upvotes
Here 'n There
PeterLN wrote: 1. A good installer would normally take care of that himself. What size of particles are we talking about? If they are specs no bigger then a 1/8" I would not be concerned since very few walls are true. If you shine a laser along the 2x4 stud faces along the wall you would see it’s never perfect. Also small specs would get compressed when the drywall gets screwed in. Personally I run a scraper along each stud face after a job to clean it up and it only takes about 20 mins to do on an average size job. I’m not a fan of the oil approach since it will react with the foam slightly. Some installer use tape on the studs when it is a retrofit and the owner failed to remove all old nails and screws. The tape takes longer to apply but is easier to remove. There is no set rules on who does the clean up but if you pick the right contractor then I believe they should take care of it. All of my jobs I mention that we do the prep and clean up of site.
I took a look at what happened as I helped him clean it up. The particles were all different sizes up to 1/2" or more. It looked like a pretty sloppy job even though I had never seen a foam job before. As for the oil I saw them apply on the This Old House TV show I too thought it didn't seem like a good idea to put oil, but I was thinking more about the wood than the foam and they only brushed it onto the stud faces not any surface the foam would be sprayed onto.
PeterLN wrote: 3. When installed properly the foam should only reduce in size in the first few hours while it is cooling. Normally the inside temperature of foam that is just sprayed is about 220F in a 2" thick pass. After it has cooled it will not shrink. If you have someone who blasts the foam very thick and hot then you may end up with unstable foam. It cures while being too hot and then is under constant tension. Again this comes back to people looking for a deal. And yes if it separates then you lose not only the vapour barrier but also the whole point of using spray foam. Once again, it comes down to being careful who you choose to do the work.
I ask because somewhere I read that it shrinks over time. Maybe they were wrong. I guess the only way to tell would be to open up a few jobs that were 10, 20, 30 years ago and look, but then it could be that, as you mention, the job was not installed properly in the first place. But has anyone ever opened up a job done 30 years ago that was done properly in the first place to see if there is any shrinkage. I guess what I am asking is how does one really know?

I have one more question. If someone wants to be very ecologically conscious is there any foam that is moreso than others? I was on Insta Insulation's website just now and they have a blurb about the 'greenwashing' of soya-based foam insulation. (http://instainsulation.com/blog/soya-sp ... -the-bean/). The fact that the soy component is 2.5% seems to support that. Do you agree?

Thanks for your very informative complete and detailed answers. I appreciate it.
Deal Addict
Jan 19, 2004
2171 posts
1017 upvotes
Toronto
Peter,
I read that after spraying with closed-cell, it should be immediately finished with drywall. Is that true?

I do intend to finish the basement but it will be an ongoing diy project. IE. Spray foamed professionally then do the drywall myself.

Thanks.
Deal Expert
User avatar
Aug 2, 2010
15196 posts
5016 upvotes
Here 'n There
Dragon120 wrote: Peter,
I read that after spraying with closed-cell, it should be immediately finished with drywall. Is that true?
I'm gonna pipe in here. I can't think of a reason that could possibly be true. Exposure to air does not affect spray foam so finishing with drywall will not change anything. I have closed cell (ie 2 lb) spray foam over the vertical concrete walls in my basement crawl space and it has been exposed for 8 years now with no change that I can see. If there is a reason why you need to finish with drywall immediately I would love to know it.
Deal Addict
Jan 19, 2004
2171 posts
1017 upvotes
Toronto
eonibm wrote: I'm gonna pipe in here. I can't think of a reason that could possibly be true. Exposure to air does not affect spray foam so finishing with drywall will not change anything. I have closed cell (ie 2 lb) spray foam over the vertical concrete walls in my basement crawl space and it has been exposed for 8 years now with no change that I can see. If there is a reason why you need to finish with drywall immediately I would love to know it.
I have bookmarked the sites- let me dig it up and post the source later. From what I read (based on my recollection), although not toxic, it recommended sealing it off/closing with drywall asap before habiting it.
Deal Expert
User avatar
Aug 2, 2010
15196 posts
5016 upvotes
Here 'n There
Dragon120 wrote: I have bookmarked the sites- let me dig it up and post the source later. From what I read (based on my recollection), although not toxic, it recommended sealing it off/closing with drywall asap before habiting it.
Apparently spray foam insulation, when cured, is inert and does not off gas either so that could not be the reason. Even so, if it did, installing a layer of drywall is not going to stop the off-gassing getting into the air in the house. Aesthetics might be a reason, lol.
Deal Expert
User avatar
Feb 8, 2014
32148 posts
15427 upvotes
Socially Distanced
Dragon120 wrote: I have bookmarked the sites- let me dig it up and post the source later. From what I read (based on my recollection), although not toxic, it recommended sealing it off/closing with drywall asap before habiting it.
Thats makes no sense, drywall is not airtight so drywalling it immediately would give you more exposure at a lower level for a longer period of time.
If its offgassing then you should not drywall for weeks or months (however long it takes) and leave your windows open and maybe even have some active air circulation (which would necessitate warm but not hot weather)
Deal Addict
User avatar
May 24, 2008
3488 posts
1532 upvotes
Toronto
Dragon120 wrote: Peter,
I read that after spraying with closed-cell, it should be immediately finished with drywall. Is that true?

I do intend to finish the basement but it will be an ongoing diy project. IE. Spray foamed professionally then do the drywall myself.

Thanks.
I think that has to do with fire regulations, but I'm sure Peter knows more about this and can comment further.
Deal Expert
User avatar
Aug 2, 2010
15196 posts
5016 upvotes
Here 'n There
Little Tim wrote: I think that has to do with fire regulations, but I'm sure Peter knows more about this and can comment further.
That is a requirement of the Ontario Building Code, below, but why must it be done'immediately' as Dragon120 read somewhere?

From the Ontario Building Code Act, 1992, as revised.

3.1.4.2. Protection of Foamed Plastics

(1) Foamed plastics that form part of a wall or ceiling assembly in combustible construction shall be protected from adjacent spaces in the building, other than adjacent concealed spaces within attic or roof spaces, crawl spaces, and wall assemblies,

(a) by one of the interior finishes described in Subsections 9.29.4. to 9.29.9.

(b) by any thermal barrier that meets the requirements of Sentence 3.1.5.12.(2), or


btw, SS 9.29.4-9 are about plaster, gypsum board, plywooding, fibreboard and particleboard respectively; and

SS 3.1.5.12.(2) refers to:
(a) not less than 12.7 mm thick gypsum board mechanically fastened to a supporting assembly independent of the insulation,
(b) lath and plaster, mechanically fastened to a supporting assembly independent of the insulation,
(c) masonry,
(d) concrete, or
(e) any thermal barrier that meets the requirements of classification B when tested in conformance with CAN/ULC-S124, “Test for the Evaluation of Protective Coverings for Foamed Plastic”.
Deal Addict
Jan 19, 2004
2171 posts
1017 upvotes
Toronto
Of course it happens when I'm trying to look-up the article and I can't find it. I know I read it on greenbuildingadvisor.com but I can't find the exact article that I stumbled upon. The other site was greenbuildingtalk.com.

I am not concerned with the temporary cosmetic visual as I will eventually board it up. I think one of the poster mention fire hazard which I believe that was the recommendation of finishing it with drywall asap (again, for gods sake I can't find the damn article).
Jr. Member
User avatar
Feb 3, 2014
187 posts
77 upvotes
Mississauga
eonibm wrote: I ask because somewhere I read that it shrinks over time. Maybe they were wrong. I guess the only way to tell would be to open up a few jobs that were 10, 20, 30 years ago and look, but then it could be that, as you mention, the job was not installed properly in the first place. But has anyone ever opened up a job done 30 years ago that was done properly in the first place to see if there is any shrinkage. I guess what I am asking is how does one really know?

I have one more question. If someone wants to be very ecologically conscious is there any foam that is moreso than others? I was on Insta Insulation's website just now and they have a blurb about the 'greenwashing' of soya-based foam insulation. (http://instainsulation.com/blog/soya-sp ... -the-bean/). The fact that the soy component is 2.5% seems to support that. Do you agree?

Thanks for your very informative complete and detailed answers. I appreciate it.
If the foam were to shrink when installed incorrectly, you would see it in the first year or two. As the seasons change from hot to cold it would add more strain on the foam.
As for the soya content...it has enough soya to classify it as a green product plus all the additional plastic bottles that are milled down. If you would have too much soya then you wouldn’t have foam.
Dragon120 wrote: Peter,
I read that after spraying with closed-cell, it should be immediately finished with drywall. Is that true?

I do intend to finish the basement but it will be an ongoing diy project. IE. Spray foamed professionally then do the drywall myself.

Thanks.
Foam does not need to be immediately covered. If someone told me that, I would be suspicious...almost as if they don’t want me to have a good look at it. While foam will degrade if exposed to UV light, it would take several weeks to a couple months for that to happen. Someone who would say that is definitely trying something fishy. Also, no one should be there on the site until it is properly ventilated or until 24hrs has passed. There is no real concern unless someone wants to do hot work around the foam i.e. welding or cutting steel.

--
Peter
Owner, VIPFoam.com
Deal Expert
User avatar
Aug 2, 2010
15196 posts
5016 upvotes
Here 'n There
PeterLN wrote: If the foam were to shrink when installed incorrectly, you would see it in the first year or two. As the seasons change from hot to cold it would add more strain on the foam.
As for the soya content...it has enough soya to classify it as a green product plus all the additional plastic bottles that are milled down. If you would have too much soya then you wouldn’t have foam.
--
Peter
Owner, VIPFoam.com
Do you mean that whether the foam shrinks or not is dependent on the quality of the physical installation or that it is dependent on having the properties of the foam itself correct, ie having the proper mix of chemicals, heat applied to the mixture, etc. and not the way it was physically applied. I would think it would depend on having the foam produced under the proper conditions, no?
Newbie
Dec 25, 2008
65 posts
4 upvotes
Quoted from a popular WALLTITE ECO sprayer

"Consumers should question the creditability of contractors that claim they sell soy based insulation."

Curious about why all the soya hype, is it really just snake oil
Jr. Member
Dec 25, 2013
104 posts
27 upvotes
Vaughan
speedbird777 wrote: Quoted from a popular WALLTITE ECO sprayer

"Consumers should question the creditability of contractors that claim they sell soy based insulation."

Curious about why all the soya hype, is it really just snake oil
With only 2.5% or less of the insulation being a soy product it seems like a bit of greenwashing to me.
Jr. Member
User avatar
Feb 3, 2014
187 posts
77 upvotes
Mississauga
eonibm wrote: Do you mean that whether the foam shrinks or not is dependent on the quality of the physical installation or that it is dependent on having the properties of the foam itself correct, ie having the proper mix of chemicals, heat applied to the mixture, etc. and not the way it was physically applied. I would think it would depend on having the foam produced under the proper conditions, no?
No, the shrinking would normally be a result of poor installation. Also, some foams are more prone to having problems then others. I cannot mention which ones.
speedbird777 wrote: Quoted from a popular WALLTITE ECO sprayer

"Consumers should question the creditability of contractors that claim they sell soy based insulation."

Curious about why all the soya hype, is it really just snake oil
Walltite Eco uses caster oil as its renewable resource for the product to be considered ‘green’, in conjunction with recycled plastic bottles. Polarfoam is soy based. The amount is not much because it would not turn to good foam when sprayed. The actual insulating properties of the foam do not depend on which oil it uses but more so on the whole chemical composition. The best way to compare them is to look at the LTTR (long term thermal resistance), density and percentage of open cell content (less is better). Don’t take my word for it, go online and download the technical data sheet for each foam that is out there and see for yourself. I believe that we mention Soya because it differentiates the product from others. Home owners will have a easier time recognizing this foam form the others because the names eventually sound similar.

--
Peter
Owner, VIPFoam.com
Deal Addict
Sep 2, 2002
2120 posts
47 upvotes
I just want to thank Peter for his help while I had problems with my spray foam contractor. He let me know what the contractor should have done the first time around, and what he (Peter) would have done differently.

And where I thought I was saving money with this contractor, I wasn't. Peter could have done it for the same money.

The contractor did come back 3 weeks later and make it right, after being irate with me on the phone for demanding he come back on a day that suited me, with 1 weeks notice. He arrived two weeks later.

To top it off, I submitted a mostly negative review to Homestars today (4/10), and the company immediately disputed the review and said I don't pay my contractors, when I actually overpaid him, in cash, before the job was complete (my mistake).

Homestars pulled my review. They still have eleven 10 star ratings.

The owner of the company called me after my review went live, just to say, "F*** you." Seriously.

I have never had a problem with companies that are active on RFD. Not that I've dealt with many, but someone who is this open and sharing of his work usually takes great pride and interest in it. If I could do it all over again, I'd use Peter's services. Though, to be fair, I'd prefer to use anyone's over the guy I got.

Want a representative pic?

[IMG]http://hansen.zenfolio.com/img/s5/v133/p698716681-3.jpg[/IMG]

That's a wall. Just a flat wall, half way up. There's supposed to be 2" of foam there. Yes, that's concrete.
Deal Guru
User avatar
Mar 13, 2004
13840 posts
5545 upvotes
Ontario
I would contact Homestars and tell them what happened to get your review back up.

Also I suggest you post a simple review about the company on many forums. But make sure you include the name/address/phone number of the company so that search engines like google will pick it up. So next time somebody searches google for "company" Reviews yours will pop up.

Top

Thread Information

There is currently 1 user viewing this thread. (0 members and 1 guest)