Litigation and repair work involving failed fire-retardant treated (FRT) plywood is still in full swing. According to some experts, however, the same chemical process that ruined the plywood is causing a slower but more dangerous problem: the degradation of roof structural systems built with FRT framing lumber. FRT plywood failures can take from two to ten or more years to develop. Problems with the plywood have been seen in thousands of condos and townhouses, where the plywood was used on roofs to prevent fires from spreading from unit to unit. Over the years, gradual degradation had caused plywood on these roofs to sag and crumble. Workers have even been known to fall right through FRT plywood roof sheathing. Fortunately, few residential units have any FRT wood in their framing. Many commercial buildings, on the other hand, have trusses or rafter systems made of FRT dimensional lumber. Now the owners
