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Maintaining the Appearance of CCA and Wolmanized Natural Select Treated Wood

No maintenance is needed to renew resistance to fungi and termites. Wolmanized® wood has a lifetime limited warranty against these organisms.

However, protection is required to maintain the wood's appearance against weather. Sun and rain cycles cause stresses in lumber and result in swelling, shrinking, warping, and cracking.

• To help protect wood against moisture damage, apply an effective brand of water repellent as soon as your project is finished or, for large projects, as sections are completed. Water repellent should be applied every year or two.
• To revitalize a dingy appearance caused by dirt and mildew, use deck brightener to clean the wood.

Coating Treated Wood

The questions we are asked most frequently do not involve the processing or longevity of treated wood, but the proper procedures for coating it. Can I paint or stain treated wood? If so, how long must I wait before applying a coating? What about water repellent? These are good questions and, because of the number of different products available - in treated wood and coatings - they do not have simple answers.

First of all, YES, you can stain or paint Wolmanized wood. Also, you can coat Wolmanized wood with a water repellent; in fact, we highly recommend it. The best way to tackle these jobs depends on the wood you have, its exposure, and the coating you plan to use.

Typical treated wood

When wood is pressure-treated, it is saturated with a liquid solution of preservative diluted in water. In a typical situation, the wood you buy is still somewhat damp.

PAINT. Do not apply paint until the wood is dry, both on the surface and internally. Otherwise, as the wood dries out, escaping moisture will cause blisters and poor adhesion in the paint. Once the wood is dry, the procedure for painting treated wood is no different from that for painting untreated wood. (We recommend against using paint on deck flooring because frequently used pathways, such as from the steps to the door, will become worn.)

STAIN. Some stains are heavily pigmented and form a film, just as paint does. The recommendations for their application are the same as those for paint, including our advice against using them for the floor of a deck. Most stains, however, are more transparent and do not block moisture movement. There are other differences, though. Stains may be oil-based or water-based. Some formulations can be used immediately; others perform best when the wood is allowed to dry for a while. Best advice: follow the stain manufacturer's instructions.

WATER REPELLENT. Most brands say that it is okay to apply a water repellent without delay, which is ideal timing. For other brands, a slight delay is recommended. Again, it is best to follow the manufacturer's instructions.

Treated wood that is re-dried after treatment

In some areas you can buy treated wood that is Kiln Dried After Treatment (KDAT) or Air Dried After Treatment (ADAT). In these processes, moisture is removed from the wood before shipment to a lumber dealer. KDAT or ADAT will be marked on each piece of wood on either the end tag or an ink stamp.

PAINT, STAIN, WATER REPELLENT The moisture content of the wood is already in balance with atmospheric moisture levels, so coating can proceed immediately.

How long must you wait before the wood is dry internally?

The time it takes for wood to dry out depends on the climate and the wood's exposure. In summer in the American southwest, deck lumber open to sunshine can dry in a few days. In cool, damp weather or when shaded by an overhanging roof or tree, it will take much longer for wood to dry. The only sure way to determine the moisture level within a piece of lumber is to check it with a moisture meter. Unless you operate a wood treating plant, you probably do not have one of these devices lying around. Therefore, we offer an estimate of the time required for the wood's moisture level to reach equilibrium with the atmosphere: as a fairly safe average, we recommend waiting six months before applying paint.