Flame Stop® II protects exterior and interior woods such as porous woods, cedar shake shingles, decking, and structural lumber. It's a water-based, post-treatment, interior/exterior fire retardant and wood preservative that penetrates the material and bonds with the cellular structure. This product penetrates the substrate and creates a self-extinguishing reaction when the treated material comes into contact with an open flame. When properly applied on certain unsealed woods, such as Douglas fir, the wood shall have a Class A rating.
It's non-toxic, non-combustible, non-carcinogenic, easy to apply, and contains no PBDEs (polybrominated diphenyl ethers), which are toxic to humans and the environment. Flame Stop® II is a Class A, one-coat system with a flame spread of 25 and smoke developed of 25 on Douglas fir.