Decay, Weathering and Epoxy Repair of Timber

Abstract

Wood used in structural applications can be a durable material. However, conditions in the surrounding environment can cause premature deterioration. Two common and related conditions are decay and weathering. An experimental investigation was conducted to evaluate the effects of weathering and decay on the epoxy repair of timber. In one phase, unprotected epoxy repaired joints were exposed to natural weathering in the southeastern United States. Joints were periodically loaded tested over a 4‐1/2 yr period and correlated to accelerated weathering tests on small epoxy bonded shear block samples. It is recommended that the dry condition shear strength of epoxy repaired Southern pine be reduced by one‐third when the repaired member is exposed to natural weathering conditions. Also, normal precautions (including preservative treatments) should be taken if the repair is exposed to weathering over a multi‐year period. A second phase consisted of epoxy repairing both lightly and heavily damaged weathered and decayed material. The strength of the repaired joints compared well with that of undamaged material. However, caution is advised in initiating such repairs without careful evaluation.