Even though pressure-treated wood is protected against termites and decay, it is subject to moisture change. You can prevent many of these moisture problems with proper construction techniques.
First, store the pressure-treated wood properly prior to use. Make sure you protect the pressure-treated wood from moisture, sun, and other elements which might cause uneven drying. Store materials under cover. Avoid direct contact with the ground. Loosen any tightly wrapped covers which may trap moisture in the wood.
Second, do not exceed recommended spans or leave long overhangs. Space the floor joists no farther than 16" on center. Use enough nails or screws to secure the wood and reduce warping. Three nails should be used across 2x6 decking. And use non-corrosive fasteners - a top quality hot-dipped, galvanized, aluminum or stainless steel fastener.
Third, water repellent coatings help keep pressure-treated wood from absorbing moisture and tend to stabilize the moisture content. Follow the manufacturer's instructions. Water repellent should be reapplied every one to two years for adequate moisture protection. If you purchased pressure-treated wood with built-in repellent, you can skip the initial application.
Following these simple steps will ensure that your pressure-treated wood decking lasts and looks great!
For more information about pressure-treated wood or a free copy of the brochure, Answers to Often-asked Questions about Pressure-Treated Wood, write the American Wood Preservers Institute, 1945 Old Gallows Rd., Suite 150, Vienna, VA 22182; or call 1-800-356-AWPI. Internet: http://www.awpi.org (NAPSI)
