PRELIMINARY DEVELOPMENT OF REMEDIAL TREATMENTS FOR THERMALLY DEGRADEDFIRE-RETARDANT-TREATED WOOD

Thermal degrade of fire-retardant-(FR-)treated plywood roof sheathing and rooftruss lumber is a complex function of wood and treatment chemi stry and field exposure conditions. Because borate-based treatments in hibit or reduce the rate of thermal degradation in wood exposed to ele vated temperatures, they may also be effective as a remedial treatment for FR-treated plywood if sufficient penetration and retention of the borate chemical can be obtained. To increase the penetration of a bor ate remedial treatment (without using excess water that might leach th e FR chemicals), we applied the borates in a glycol/water mixture. Our preliminary results indicate that borate/glycol remedial treatments c an partially mediate thermal degrade of FR-treated plywood. Further wo rk is now underway.