Thermal and Ignition Barrier Paint

Do you need a thermal barrier?

Yes, absolutely. If you put spray foam insulation in a building, it needs a thermal barrier. That’s what separates it from the occupied spaces. If there’s a fire in the building, a thermal barrier keeps the combustible spray foam from the flames to increase fire resistance. The International Residential Code (IRC) and Internation Building Code (IBC) both include requirements for thermal barriers. The standard prescriptive material that can be used as a thermal barrier is 1/2″ gypsum board (a.k.a. drywall or sheetrock).

Do you need an ignition barrier?

This is where things get a little tricky. If a home has spray foam insulation in an attic or crawl space, the building code requires using materials or assemblies that offer some fire resistance but not as much as is required for a thermal barrier. According to the IRC and IBC, an attic or crawl space needs an ignition barrier over the spray foam if the space can be accessed but will not be used for storage or auxiliary living space. You don’t need an ignition barrier if the space cannot be accessed without cutting into it, if it is not connected to other spaces, and if it does not communicate with other spaces