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Posted: Sep 27, 2008 05:33 PM	spray foam I was told by an installer of spray foam that open cell spray foam does not out-gas and lose R value like closed cell spray foam. I would prefer to use the higher R value product in new construction, but not if it poses a health problem and it loses its R value. Thanks.
mason Posted: Sep 28, 2008 05:55 PM	The closed cell foam typically uses a blowing agent that provides around 6 to 6.8 R aged value per inch. The initial R value starts higher and due to outside air infiltrated into the exterior foam cells, the R value is reduced, (typically around 5 to 10%). So a foam that starts at 7.5 would end up around 6.8. FTC requires that foam plastics be tested at their aged R values. For sprayfoam that is at 6 months. By this time more than 90 percent of the R value reduction has taken place. The remaining 10 percent of R value reduction takes place over the life of the product. So conservatively you can count on at least an R value of 6 with the closed cell foam. As for outgassing. There are no studies that indicate that closed cell foam outgasses harmful chemicals into your building. The most harmful chemical in sprayfoam (both open and closed cell) is the isocyanate, then the catalyst and the fire retardants. Again, both open and closed cell foam contain similar types of catalyst and fire retardant packages. The main difference is the blowing agent and in closed cell foams that is predominately HFC 245 fa blends. This chemical is not considered a hazardous material and has not been known to cause harm to humans or animals. For additional information go to my website and check out the articles on "Learning the Difference Between 1/2 lb and 2 lb SPF" and "Understanding R values" masonknowles.com

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Posted: Sep 27, 2008 05:33 PM

spray foam

I was told by an installer of spray foam that open cell spray foam does not out-gas and lose R value like closed cell spray foam. I would prefer to use the higher R value product in new construction, but not if it poses a health problem and it loses its R value.

Thanks.

mason

Posted: Sep 28, 2008 05:55 PM

The closed cell foam typically uses a blowing agent that provides around 6 to 6.8 R aged value per inch. The initial R value starts higher and due to outside air infiltrated into the exterior foam cells, the R value is reduced, (typically around 5 to 10%). So a foam that starts at 7.5 would end up around 6.8.

FTC requires that foam plastics be tested at their aged R values. For sprayfoam that is at 6 months. By this time more than 90 percent of the R value reduction has taken place. The remaining 10 percent of R value reduction takes place over the life of the product.

So conservatively you can count on at least an R value of 6 with the closed cell foam.

As for outgassing. There are no studies that indicate that closed cell foam outgasses harmful chemicals into your building. The most harmful chemical in sprayfoam (both open and closed cell) is the isocyanate, then the catalyst and the fire retardants. Again, both open and closed cell foam contain similar types of catalyst and fire retardant packages.

The main difference is the blowing agent and in closed cell foams that is predominately HFC 245 fa blends. This chemical is not considered a hazardous material and has not been known to cause harm to humans or animals.

For additional information go to my website and check out the articles on "Learning the Difference Between 1/2 lb and 2 lb SPF" and "Understanding R values"

masonknowles.com

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