Ignition Barrier/ unvented attic | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

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Posted: Dec 31, 2007 10:47 PM	Ignition Barrier/ unvented attic I want to thank you for helping me through my foaming process. I definitely want to say I LOVE IT. I dont haqve heat on,(Dec) and it stays nice with sunlight only entering windows. My next question which we touched on before was ignition barriers. I have alot of vaults and vertical walls which go to roof rafters. My attic is unvented, and contains my ductwork(Not covered)and some basic wires for circuits below in rooms. My attic access hatch is only to allow service of those ducts.(Min. size 22x30) Doesn't that fall under article 314.5.3? Or does that only relate to themal barriers? My attic would have been a standard 27'x34', 5:12 pitch vented attic, however, I foamed all the way up to ridge and have some standard 8' celings and some vaults. The area above collar tyes is very small. I cannot store in the attic and some sections are hard to even manueveur in, so how am I to cover it with 1 1/2 of fiberglass insulation. Is there another option, I heard of a spray coating that meets igniton codes, is there such a thing, and do I even have to do that for my attic?
mason Posted: Jan 01, 2008 09:18 AM	Yes, you have to cover the foam with a building code approved ignition barrier. That includes 1 -1/2 mineral fiber, 1/4 inch fiberboard, wood paneling etc. There are a few intumescent (spray on) coatings that have been tested and issued ICC Evaluation Services Reports with specific sprayfoams. However, the coatings must be used with the specific foam it was tested in exactly the same configuration. Check with your foam supplier to see if they have their foam tested with a spray on coating. If not, you need to use the code listed igntion barriers.

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Posted: Dec 31, 2007 10:47 PM

Ignition Barrier/ unvented attic

I want to thank you for helping me through my foaming process. I definitely want to say I LOVE IT. I dont haqve heat on,(Dec) and it stays nice with sunlight only entering windows.
My next question which we touched on before was ignition barriers. I have alot of vaults and vertical walls which go to roof rafters. My attic is unvented, and contains my ductwork(Not covered)and some basic wires for circuits below in rooms. My attic access hatch is only to allow service of those ducts.(Min. size 22x30) Doesn't that fall under article 314.5.3? Or does that only relate to themal barriers? My attic would have been a standard 27'x34', 5:12 pitch vented attic, however, I foamed all the way up to ridge and have some standard 8' celings and some vaults. The area above collar tyes is very small. I cannot store in the attic and some sections are hard to even manueveur in, so how am I to cover it with 1 1/2 of fiberglass insulation. Is there another option, I heard of a spray coating that meets igniton codes, is there such a thing, and do I even have to do that for my attic?

mason

Posted: Jan 01, 2008 09:18 AM

Yes, you have to cover the foam with a building code approved ignition barrier. That includes 1 -1/2 mineral fiber, 1/4 inch fiberboard, wood paneling etc.

There are a few intumescent (spray on) coatings that have been tested and issued ICC Evaluation Services Reports with specific sprayfoams. However, the coatings must be used with the specific foam it was tested in exactly the same configuration.

Check with your foam supplier to see if they have their foam tested with a spray on coating.

If not, you need to use the code listed igntion barriers.

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