FRT (fire retardant treated) Plywood

FRT plywood is a sheathing  treated with a chemical to prevent flame spreading in the event of the fire. It was used on townhouses and condos roofs, 4 feet on each side (sometimes more) of the walls separating each individual unit in the late 1970’s to early 1980’s. Some types of this plywood have been identified as defective, but not all of them! It was discovered that a chemical reaction occurs at a lower attic temperature than expected, which weakened the plywood and caused structural failure. A visual inspection may not be able to tell you whether the materials used on a roof are defective. FRT plywood is usually darker in color. Look for the following:

  • A white powdery substance or stain on the plywood visible in the attic, caused by the leakage of chemicals
  • A darkening of the wood, resembling black coffee
  • A charred appearance to the plywood
  • Plywood that becomes brittle or cracks and crumbles easily
  • A leak in the roof
  • The roof on the exterior might appear wavy
  • FRT plywood cannot be repaired. If the FRT plywood on the roof is defective, it must be replaced.
IT IS RECOMMENDED THAT REPAIR WORK BE PERFORMED BY A LICENSED PROFESSIONAL.
You may save yourself, your loved ones, employees or customers by implementing a complete carbon monoxide safety plan and including CO detector badges as part of the basic safety equipment. Visit Carbon Monoxide Safety for more information and Carbon Monoxide Safety Products to begin ensuring your home, building or vehicle is safe from CO gas.