No-Burn® Plus Successfully Tested as an Ignition Barrier over Polyurethane Foam
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Before Foam and No-Burn® Plus Installation |
After Foam and No-Burn® Plus Installation |
No-Burn® Plus is an Intumescent Protective Coating that meets code requirements as a protective coating over spray polyurethane foam in crawl space and attic areas.
This is a cost-effective, one coat application that can also be applied to the wood structure at the same time, to create a non-combustible environment.
No-Burn® Plus is a water-based system that cures within 24 hours. This coating provides a long-term protective shield whose only purpose is to prevent the direct impact of a flame source on the spray polyurethane foam surface.
Spray foam insulation is a polyurethane derivative and is made from two components that are mixed on the job before application. In the liquid spray form, the material expands about 100 times its original volume as it dries. Once it has dried, the material can be destroyed by flames, but it will not sustain combustion. The material should not be installed within 2 inches (50 mm) of a heat-emitting device where the temperature can exceed 180 °F (82 °C). It cannot be used in electrical outlet or junction boxes.
If the material is used in spaces where there is normal and routine human activity, it must be protected by a 15-minute thermal barrier consisting of 1/2-inch (12.7 mm) gypsum wallboard or equivalent protection that meets the local building code for thermal barriers and will limit the average temperature of the unexposed side to no more than 250 °F (121 °C) after 15 minutes of exposure.
If the material is applied in an attic or crawl space where the only access is for utility service, it must be protected by an ignition barrier consisting of 1- 1/2-inch-thick (38 mm) mineral fiber insulation; 1/4-inch (6.4 mm) wood structural panel, particleboard, or hardboard; 3/8-inch (9.5 mm) gypsum wallboard; corrosion-resistant steel having a base metal thickness of 0.016 inch (0.4 mm) or other approved material that is installed so the foam plastic is not exposed.
For additional information, refer to NFPA® 5000, Building Construction and Safety Code®, the International Residential Code®, and the International Building Code® chapters on “foam plastics.”
