How to Buy Pressure-Treated Lumber: Know Your Stuff

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The Job: Build a planter with pressure-treated lumber.

Pressure-treated lumber is rated by the amount of chemical infused in it per cubic foot of wood. This is stated on the tag stapled to the lumber’s endgrain. Ground-contact rated lumber has .40 pounds of preservative per cubic foot. Above-ground rated lumber has .25 pounds. Use the .40 variety for posts and flower planters, for example.

There’s nothing wrong with pressure-treated lumber with .25 pounds of preservative per cubic foot of wood. It’s just that it won’t last as long in soil contact as the product at left. It’s fine for fence slats, handrails and the portions of exterior steps that are not in contact with the ground. Treat the cut ends of both .40 and .25 types with preservative.

PLUS: Wood Buyer's Guide