Dimensional Stability of Fire-Retardant-Treated Laminated Veneer Lumber

Abstract

Test of fire-retardant-treated (FRT) laminated veneer lumber (LVL) indicated moisture gain under adsorption and moisture loss under desorption conditions. The moisture content of FRT specimens increased considerably under adsorption conditions compared with control specimens, while it was not found to be a significant difference under desorption conditions. The statistical findings revealed that impregnation with chemical salts had significant effects on the expansion properties. Fire-retardant treatment also had meaningful effects on the swelling properties. However, the expansion and swelling properties of the LVL were not affected significantly by the veneer drying temperature. Generally, equilibrium moisture content of LVL decreased with increasing veneer drying temperature. The interactions between fire-retardant chemicals and veneer drying temperature were also found to be insignificant.