Macrocarpa is suitable for decking and does not need to be treated. Its natural durability can be sufficient for this purpose.
However, its durability is unreliable in moderate-high decay hazard situations, and occasional failures may occur within 10-15 years. Therefore it is not recommended in-ground, such as for posts and piles.
See Macrocarpa on the species section.
See the how-to guide for information on building a deck.