Description:
Joints were fabricated from different combinations of untreated and fireretardant-
treated (FRT) Douglas-fir dimension lumber and 3/8-inch plywood. Eight types of
fasteners and three fire-retardant treatments were tested. Joint specimens were exposed 2 and 7 years in cold, standard, and warm-humid conditions, then tested in lateral bearing. Best overall performance was from joints made with 6d hot-dipped galvanized nails; 6d monel nails were next best. Although results from several types of fasteners used in treated wood and exposed in cold and standard conditions were as good as results obtained from untreated controls, most specimens exposed in warm, humid conditions were reduced in strength; some were reduced to zero strength.