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thermal barrier Post New Topic | Post Reply
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Jill Ludvickson
Posted: Jul 23, 2007 07:16 PM
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thermal barrier
We are spraying foam to the underside of the roof deck in a custom home. Some of the areas have vaulted ceilings. The builder is planning on covering up the foam with 1/2" plywood. I found on foamtech website that 15/32" plywood is a thermal barrier. Is this true and if so is there back up for an inspector.
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mason
Posted: Jul 24, 2007 08:07 AM
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1/2 OSB or plywood will provide a thermal resistance that may be sufficient. However, it is up to the installer or foam manufacturer to provide documentation to the building code official. They will require either a ICC ES Evaluation Report showing that the 1/2" plywood passed thermal barrier assembly tests or room corner tests over the sprayfoam (showing that it limits the temperature of surface of the plywood to less than 250 degrees F after 15 minutes of fire exposure in the room corner tests. ) By the way, what is builder going to cover the plywood with? If it is gypsum board that is a thermal barrier. |
