Insect damage in the sapwood of structural timbers
When wood-boring insect flight holes are discovered in a structural timber there is a fear the remainder of the timber will succumb to attack. This is not the case. Without chemical modification of the timber by fungal decay, only the sapwood in susceptible to insect attack at moisture contents over approximately 18%. The heartwood will remain impervious to attack due to the various chemicals it contains that give it its durability. With this knowledge, it is possible to explain the patterns of insect damage frequently found in structural timbers in buildings. 
The photograph below shows deathwatch and furniture beetle damage in the sapwood of a half post. The blanket treatment of building timbers with insecticide when such damage is found is clearly unwarranted: there is no damage in the heartwood and it is not at risk of attack.
The photograph below shows deathwatch and furniture beetle damage in the sapwood of a half post. The blanket treatment of building timbers with insecticide when such damage is found is clearly unwarranted: there is no damage in the heartwood and it is not at risk of attack.
posted by Ridout Associates at
10:32
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