HOW DO NATURALLY DURABLE WOOD SPECIES COMPARE TO TREATED WOOD?
The heartwood of naturally durable species such as western red cedar, yellow cypress and white cedar will all resist decay to some degree, but it is variable. The amount and type of natural fungi-toxic chemicals deposited in the heartwood determine how durable the wood is. The sapwood of all species is considered non-durable. Heartwood of second growth may be less durable than the best of the old growth but probably less variable. Wood that has been treated to CSA standards will deliver more reliable durability performance on average than a naturally durable species.
