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Raymond Brooks Posted: Nov 28, 2008 07:58 PM	Cal. Foam Roof Mason, I have a customer doing foam roofs in California. He is doing a complete tear off to the wood deck. He says he needs to screw down sheetrock before he can foam. Apparently, they require an ignition (or thermal?) barrier between interior and foam. He says this is virtually impossible to do on this roof due to mechanicals, pipes, etc. Question 1) Is this true and am I understanding this correctly? Question 2) If I do understand this correctly, can they spray apply an ignition coating such as TRP2, Aldo, Contego first, foam, then topcoat? The procedure as I understand it makes no sense and makes foam roofing costly. Any thoughts?
mason Posted: Nov 29, 2008 08:53 AM	It depends on the foam and coating system. If the project requires a class A roof covering as tested in accordance with UL 790 (ASTM E 104), then you might check with various coating suppliers to find a foam and coating system that is rated class A on combustible deck (wood). Most building codes require a class A, B or C on combustible decks, but some insurance coverage may require a class A. If you cannot find a class A system on wood deck, you would need to fasten a thermal barrier over the wood deck. Gypsum drywall works as well as Dens Deck. The intumescent coatings are not thermal barriers and would meet the requirements.
mason Posted: Nov 29, 2008 08:58 AM	In the last post, it should read that intumescent coatings would not work as thermal barriers so in this project would not meet the requirments. (I am having trouble editing the posts for some reason)
Gerry Wagoner Posted: Nov 30, 2008 08:12 PM	Likewise.

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Comments

Raymond Brooks

Posted: Nov 28, 2008 07:58 PM

Cal. Foam Roof

Mason,

I have a customer doing foam roofs in California. He is doing a complete tear off to the wood deck. He says he needs to screw down sheetrock before he can foam. Apparently, they require an ignition (or thermal?) barrier between interior and foam. He says this is virtually impossible to do on this roof due to mechanicals, pipes, etc. Question 1) Is this true and am I understanding this correctly? Question 2) If I do understand this correctly, can they spray apply an ignition coating such as TRP2, Aldo, Contego first, foam, then topcoat? The procedure as I understand it makes no sense and makes foam roofing costly. Any thoughts?

mason

Posted: Nov 29, 2008 08:53 AM

It depends on the foam and coating system. If the project requires a class A roof covering as tested in accordance with UL 790 (ASTM E 104), then you might check with various coating suppliers to find a foam and coating system that is rated class A on combustible deck (wood). Most building codes require a class A, B or C on combustible decks, but some insurance coverage may require a class A.

If you cannot find a class A system on wood deck, you would need to fasten a thermal barrier over the wood deck. Gypsum drywall works as well as Dens Deck. The intumescent coatings are not thermal barriers and would meet the requirements.

mason

Posted: Nov 29, 2008 08:58 AM

In the last post, it should read that intumescent coatings would not work as thermal barriers so in this project would not meet the requirments. (I am having trouble editing the posts for some reason)

Gerry Wagoner

Posted: Nov 30, 2008 08:12 PM

Likewise.

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