How to reduce yard losses and customer complaints on pressure treated lumber

EIOR most building material dealers, pressure treated I-' wood is a major contributor to lumber sales.

It is also a contributor to profits, although these profits are reduced by unsaleable pieces that must be culled and by the cost involved in appeasing customers who are upset about excessive warping.

While contractors and do-it-yourselfers have readily accepted pressure treated wood, one question is frequently heard in lumber yards: What can you do to reduce warp and crook in treated lumber? Resolving complaints and coordinating exchanges require time and expense that store personnel could better spend on selling products.

There is no need, however, for yard loss or customer complaints to cut into your profits; proper handling and storage of pressure treated wood will minimize problems.

Warping-such as bending, twisting, bowing and cupping-results from stresses occurring within the wood as it dries down to the moisture level of the environment. Such changes take place in both treated and untreated wood as they dry.

The degree of warping depends on s.everal factors, including unevenness in drying, species of wood, grain pattern, drying rate and natural defects. A freshly cut tree contains much moisture. As this moisture evaporates into the air. the wood shrinks in width and thickness.

In the production of treated wood, lumber is impregnated with preservative solution, again becoming full of moisture. Following processing, the lumber dries out and is once more subject to internal stresses and shrinkage.

To a lesser but still noticeable degree, there are surface stresses created in exposed lumber every time it dries out after heavy precipitation. This can cause checks, splits and raised grain.

Story at a Glance

Proper storage and handling decreases yard losses and customer complaints.

What you can do

There is no way known to eliminate warping completely, but you can minimize it by balancing the drying of your stock. You have two choices:

(1) Do not allow your lumber to dry out, or

(2) Help all sides dry out evenly.

If you receive bundles of lumber in "dead packs"-lumber banded together without stickers separating the piecesit is best to keep the wood wrapped or covered and out of the sun and wind. In other words, try not to let it dry out while in your possession. When the sun dries the topside of the lumber faster than the bottomside, problems can result.

If your incoming lumber is separated by stickers, air is able to circulate around the lumber. You must then shield only the top layer from the sun or turn the top pieces occasionally. Either way the drying will be evened out.

For protection against moisture and sunlight, some buyers specify bundles that are paper-wrapped. This packaging, available from quality treaters, is particularly beneficial if the wood may be in inventory for a while

In the ideal situation, lumber is stored in an open, wellventilated shed and protected from direct sunlight. Indoor winter storage requires special watchfulness to prevent degrade. Closed, heated buildings with low humidity accelerate drying and increase the potential for warpage.

In addition to using good storage methods, you can reduce loss by stocking lumber that is less prone to warp. Some premium brands of decking have a kerf down the bottomside of each piece; these cuts help relieve the stresses that cause dimensional change.

There is also less warping in lumber that has been redried after treatment, either in a kiln (KDAT) or air dried. Re-drying removes moisture before the wood is shipped.

Another alternative is buying wood that has been pressure treated with a water repellent as well as a preservative. Products such as Wolmanized Extra lumber absorb and release moisture at a slower rate than conventional treated wood. Consequently, drying proceeds more evenly and warping is less likely to occur.

There is convincing evidence that consumers will pay more for wood with built-in water repellency. As a result, such lumber generates higher margins while decreasing yard loss and customer complaints.

You can also help your customers reduce their warpage problems (and therefore future complaints to you) by advising them to apply water repellent coatings periodically, avoid long spans and excessive cantilevers, and use a sufficient number of fasteners.

Even though dimensional change and warping can't be avoided entirely, they do not have to add to your problems or your costs. You can reduce degrade and customer dissatisfaction if you store your stock with drying in mind and if you take care to rotate your inventory. There are side benefits, too. An orderly, protected inventory impresses customers, reduces hazards, and makes material handling more efficient.