All timber products should be treated in their final shape and form. Any surface exposed by drilling or cutting must be re-treated with a suitable cut end preservative.
Failure to re-treat may negate the value of the preservative and is a requirement of the guarantee. Rip sawing, thicknessing and planing are not permitted unless the timber is subsequently re-treated to the original specification.
See Koppers Performance Chemicals Resealing Technical Data Sheet (TDS) for more information.