Lyctus wood borers as the name implies attack on the sapwood
Lyctus wood borers are a type of timber pest that only attack the sapwood of certain susceptible species of hardwood timber. Since it is a requirement that structural timbers contain no more than 25% Lyctus (soft bits) susceptible sapwood, these borers are not normally associated with structural damage. Replacement of affected timbers is not recommended or required (usually) and treatment is not approved. Where decorative timbers are affected the emergence holes may be considered unsightly in which case timber replacement is the only option. Powder post beetles mostly attack during the first 6-12 months of service life of timber.
Due to Timber Grading, Less than 25% of Structural Hardwood Timber is ‘Sapwood’
As only the sapwood is destroyed, larger dimensional timbers (such as rafters, bearers and joists) in a house are seldom weakened significantly to cause collapse. In small dimensional timbers (such as tiling and ceiling battens) the sapwood may be extensive, and its destruction may result in collapse. Replacement of these timbers is the only option available. Here we have another good reason to have a Pest and Building Inspection carried out on Sydney homes.