How to Select Wood for a Deck

The quality of your deck relies on the quality of the lumber.

Incorrectly selecting wood for your deck can leave you with substandard lumber or improperly prepared lumber not suited for building. Additional problems can come from selecting the wrong species of wood that won't withstand proper loads or might attract insects. Correctly selecting lumber for your deck ensures your family can enjoy relaxing on it safely. Selecting the right wood also ensures your investment won't be eaten by bugs.

Instructions

1. Examine the lumber codes stamped in orange, red or blue on the lumber, looking for the letters KD or KDAT that indicated kiln dried or kiln dried after treatment, meaning the wood was heat dried or kiln dried after treatment with pressure- and flame-retardant chemicals. Pressure treatment helps the wood withstand higher loads, and flame-retardant chemicals make the wood more resistant to flames or heat.

2. Examine the wood for knots. Knots represent weak points in the wood and come from points where a branch grew out of the tree. Although lumber yards sell premium wood with fewer knots, inspect each plank for knots, rejecting knotty wood.

3. Examine the wood for straightness by standing at one end and noting the curvature. Although some slight curves called bowing or scalps disappear when you nail the plank into place, curves make construction somewhat more difficult.

4. Select "heartwoods" when considering softwoods like cedar or redwood. Heartwood represents the strongest cuts from the innermost (heart) of the log.

5. Select a 25 percent preservation treatment for all wood you use above ground and a 60 percent preservation treatment for any posts that you will bury halfway into the ground and use as posts. Preservation treatment consists of chemicals designed to keep the wood from wet-rotting.

Tips & Warnings

• Curved wood might suffice for siding or some support posts, but select the most straight wood you can find for deck flooring.

References

• The Seattle Times; How to Select Wood for a Deck; Gene Austin