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.
Due to the molecular bond with the substrate, the life of the flame retardation is indefinite for most interior applications. It does contain polymers that maintain the fire retardation for up to five years for exterior applications and reapplication is recommended every five years. And because it does not alter the structural integrity of the wood the way pressure treatment does, it also functions as a wood preservative, dries clear, and can be easily applied by spraying, immersing, brushing, or rolling.