# Outgassing ?



## tomstractormag (Feb 23, 2007)

I was wondering what if any problems there are with outgassing from spray foam insulation?
This will be on new construction not a retrofit.
I like the concept and not needing walls extra thick and still have great insulation.
Thanks. Tom in Lancaster PA


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## Michael Kawalek (Jun 21, 2007)

Yes, but any construction has some outgassing, even if it's wood. You could still do it, though you might want to leave windows open more than is economical just so the solvents can evaporate.

Can you get this done right now, before really cold winter weather sets in? Even a month of evaporation might be enough if you can keep the windows open that long. I wouldn't wait till below freezing weather gets here and you have to button the house up tight. In a tight house though it might take 6-12 months for it to all completely evaporate away.

When you say "new construction" how long before the structure is closed tight, and how long before it's occupied? If it will sit there a while before occupation, I'd say spray away and don't worry at all.


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## CamM (Dec 6, 2008)

Outgassing isn't great, but unless a person is hypersensitive I doubt anything would happen. I've seen vids of people spraying themselves with the stuff without any effects. If you're concerned about outagassing I'd avoid stuff like OSB and there is non-formaldahyde based plywood out there.


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## artificer (Feb 26, 2007)

The foam, once cured, should have no/little outgassing. I would be worried more about the osb/plywood used. Or maybe the China supplied drywall that breaks down to emit corrosive oxides.

If the foam wasn't so expensive, I would use it. Around here its $2/board foot for the first inch, and $1/bd ft after that. I wanted a minimum of 2 inches, preferably 3 inches. $3-$4/sqare foot was just too much for me.

Michael


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## mightybooboo (Feb 10, 2004)

The thing that bothers me about the foam is not only it isnt fire proof,but actually burns quite well while emitting very toxic smoke.

Unless thats changed its a flat out deal killer in my book.

I worry that stuff could do a 'Final Solution' on you before you even knew you had a fire.Inhalation is the big killer on fires,right? Think Ive heard that.


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## artificer (Feb 26, 2007)

mightybooboo said:


> The thing that bothers me about the foam is not only it isnt fire proof,but actually burns quite well while emitting very toxic smoke.
> 
> Unless thats changed its a flat out deal killer in my book.
> 
> I worry that stuff could do a 'Final Solution' on you before you even knew you had a fire.Inhalation is the big killer on fires,right? Think Ive heard that.


... which is why every code says the foam has to be covered with a thermal barrier, which is typically 1/2" gypsum board/drywall.

Your carpeting, drapes, and foam couch stuffing are going to be spewing massive amounts of smoke before the foam even gets a chance to be involved.

Most foams are flame resistant until you have a fully involved fire, and the drywall is gone. The problem is that then the foam burns. However, if you were still in the house, you wouldn't be surviving the fire by then anyway. The toxicity of the smoke is supposed to be less than that of white pine.

I don't know about the accuracy of this, but I don't have a problem believing it. For me, cost was the deal buster.

Michael


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## tamsam (May 12, 2006)

I don't know about now but in the late 60's we used a foam to insulate the floors of the race cars. I have seen some buildings done with it. The type we used was almost fire proof as if you put a torch to it it burn until you took the torch away. The great stuff and others will burn like wood. As well as I can remember their was no noticeable smells to it. We did do a couple rooms with it. Sam


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## texican (Oct 4, 2003)

artificer said:


> The foam, once cured, should have no/little outgassing. I would be worried more about the osb/plywood used. Or maybe the China supplied drywall that breaks down to emit corrosive oxides.
> 
> If the foam wasn't so expensive, I would use it. Around here its $2/board foot for the first inch, and $1/bd ft after that. I wanted a minimum of 2 inches, preferably 3 inches. $3-$4/sqare foot was just too much for me.
> 
> Michael


Is that square footage figure based on floor square footage, or actual area to be foamed? I'm thinking they probably would have to do actual foamed size, otherwise a 20' high wall would 'burn them'.

If it costs that much, it's a non starter for me.


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## SolarGary (Sep 8, 2005)

artificer said:


> The foam, once cured, should have no/little outgassing. I would be worried more about the osb/plywood used. Or maybe the China supplied drywall that breaks down to emit corrosive oxides.
> 
> If the foam wasn't so expensive, I would use it. Around here its $2/board foot for the first inch, and $1/bd ft after that. I wanted a minimum of 2 inches, preferably 3 inches. $3-$4/sqare foot was just too much for me.
> 
> Michael


Some of the builders around here spray about an inch of foam in each stud cavity, and then fill the rest with cellulose or FG.
The idea is that even 1 inch of foam seals everything up for no infiltration, and using the cheaper insulation for the rest saves money -- makes some sense to me.

I think that an inch of rigid foam board on the outside of the studs is also a good idea to reduce thermal bridging through the studs.

Gary


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