Borate compounds are found in naturally occurring deposits and are a combination of boron and oxygen. Borates are very effective at killing wood destroying insects, fungi, and may also have some fire-retardant properties. The ability of borate compounds to diffuse in water is both an advantage and disadvantage. It allows the chemical to penetrate deeply into wet wood; therefore borate treatments do not require the wood to be incised prior to treatment. However, this property allows the borate chemical to leach out of the wood if exposed to wetting. As such, borate treated lumber and plywood must be protected from the weather and are not labeled for direct ground contact. Borates are also known for their relative safely and economy.

Uses: Sill plate, joists, studs, roof trusses, blocking, rafters, beams

Species: Douglas-fir, Hem fir, Southern Yellow Pine, Spruce-Pine-Fir

Color: Clear. Typically, a blue or green tinted dye is added to the treating solution to distinguish it from untreated wood