BU575 Timber treatment (2014)

Timber is a natural organic material. Many species can be subject to insect attack and fungal decay under damp conditions. Protecting the timber with chemical wood preservatives increases resistance to fungal decay and wood-boring insects.

This bulletin outlines the requirements for timber durability and the preservative options available and incorporates information resulting from Amendment 5 to NZS 3640:2003 Chemical preservation of round and sawn timber.

This bulletin updates and replaces Bulletin 538 of the same name.

The bulletin covers:

• Building Code and standards
• timber durability and preservation
• preservative treatments
• treated timber in use
• in situ treating of existing framing timbers.