Cedar lumbar is naturally resistant against insect attack and decay. Wolmanized lumbar is usually Red Pine, Southern Yellow-Pine or Douglas Fir. These lumbar species are milled like Cedar then pressurized with a chemical mixture of chromate, copper and arsenate (cca) to resist insect attack and decay. Please contact us about the chemical additives. We can build your deck with non-arsenate lumber. We also build fire retardant lumber, which is excellent for multi-level porches, and roof decks.