vegeta82
Member
I have a unique request I am going back and forth with.
The most relevant code section is. (2015 IRC)
R316.4 Thermal barrier. Unless otherwise allowed in Section
R316.5, foam plastic shall be separated from the interior
of a building by an approved thermal barrier of not less than
1/2-inch (12.7 mm) gypsum wallboard, 23/32-inch (18.2 mm)
wood structural panel or a material that is tested in accordance
with and meets the acceptance criteria of both the Temperature
Transmission Fire Test and the Integrity Fire Test of
NFPA 275.
Builder wants to install a skim coat of Spray Foam on the ceiling of a house from the attic side after gypsum board installed. (likely 2" of Closed Cell Foam). He then wants to install a blown in insulation over this foam to complete the system and get the proper R Value.
His hope is that he will not have to install any further product to achieve the attic ignition/thermal barrier. I believe he would need a thermal barrier because there will be storage space in the attic.
I have read this morning at length about the concept of either fiberglass, cellulose, or mineral fiber insulation complying as a thermal barrier.
But i can find nothing that supports the idea that a blown insulation meets NFPA 275. Practically speaking however with 6" plus of Cellulose on top of the foam i can't see much risk of the Foam being a potential hazard.
Some of the more interesting items i found. And these are both from Foam Advocates. But even here nothing I see shows it meets NFPA 275.
The most relevant code section is. (2015 IRC)
R316.4 Thermal barrier. Unless otherwise allowed in Section
R316.5, foam plastic shall be separated from the interior
of a building by an approved thermal barrier of not less than
1/2-inch (12.7 mm) gypsum wallboard, 23/32-inch (18.2 mm)
wood structural panel or a material that is tested in accordance
with and meets the acceptance criteria of both the Temperature
Transmission Fire Test and the Integrity Fire Test of
NFPA 275.
Builder wants to install a skim coat of Spray Foam on the ceiling of a house from the attic side after gypsum board installed. (likely 2" of Closed Cell Foam). He then wants to install a blown in insulation over this foam to complete the system and get the proper R Value.
His hope is that he will not have to install any further product to achieve the attic ignition/thermal barrier. I believe he would need a thermal barrier because there will be storage space in the attic.
I have read this morning at length about the concept of either fiberglass, cellulose, or mineral fiber insulation complying as a thermal barrier.
But i can find nothing that supports the idea that a blown insulation meets NFPA 275. Practically speaking however with 6" plus of Cellulose on top of the foam i can't see much risk of the Foam being a potential hazard.
Some of the more interesting items i found. And these are both from Foam Advocates. But even here nothing I see shows it meets NFPA 275.
Fire Barrier
FOAM-TECH creates superior insulation and environmental control solutions by installing safe, cost-effective, and environmentally-friendly polyurethane foams. We have the capabilities to spray and inject a variety of foam systems to achieve a high R-value while providing both effective vapor...
www.foam-tech.com