Decks made of pressure-treated wood should be sealed annually


July 04, 1992|By Gene Austin | Gene Austin,Knight-Ridder News Service

Q: I have a deck built of pressure-treated lumber that absorbs rainwater like a blotter. What kind of product do you recommend to seal it? I am told that some sealers do more harm than good?

A: Some owners of pressure-treated structures assume the wood needs no protective treatment, and this view at one time was encouraged by manufacturers of the wood.

However, most pressure-treated wood should have periodic sealing against moisture, preferably every year or so. Although the wood is resistant to rot and insect attacks because of the pressure treatment, it can warp, split and develop mildew if not protected from the effects of water.

Generally, the water protection should be started soon after construction, although some new, premium grades of pressure-treated wood are sold with a built-in water sealer that lasts a couple of years (Wolmanized Extra is an example).

Wolman RainCoat, made by one of the big names in pressure-treating, is a widely sold water repellent that is a good choice for use on pressure-treated wood, although it can also be used on other types of wood.

RainCoat is available in clear and "natural toner" formulas. The latter colors the wood slightly. The manufacturer says RainCoat can be applied to wood immediately after construction; a waiting period of several months is needed for some sealers.

For more information on RainCoat, call (800) 556-7737.

However, most of the water-repellent sealers sold at home centers, paint stores and lumber yards are suitable for pressure-treated wood as well as other outdoor woods such as cedar and redwood. The directions for some, such as Thompson's Water Seal, specify pressure-treated wood as a suitable use.

Q: For the past several years I've observed carpenter ants in my house, especially in the kitchen. How can I control these ants before they cause damage to the house?

A: Carpenter ants are generally attracted to moist, rotting wood, which they use for nesting, not food. There is a good chance that a plumbing leak, roof leak or other moisture problem is creating conditions the ants like in your kitchen. You should check carefully for such problems and have them corrected, since they can do more damage than the ants.

Most home centers and garden-supply centers also stock insecticides that are effective against carpenter ants. A reader wrote me that she had eliminated an invasion of these ants by using an ant-killer dust made by Ortho.

Read and follow directions for any insecticide carefully, since using these chemicals in the home can be dangerous, especially to children and pets.

If do-it-yourself treatment and correcting moisture-causing conditions doesn't eliminate the ants, it's best to call in a pest-exterminator.

Q: We have cedar shingles on our church, and want to preserve the original appearance rather than let them weather to a gray or black color. We're confused about possible treatments. Can you help?

A: It is difficult to keep natural wood from darkening or weathering. The graying of most wood is caused by ultraviolet rays from the sun, and I know of no way to screen these rays out completely except by painting the wood, which you obviously don't want to do.

Using a clear sealer or finish that contains ultraviolet (UV) screen or inhibitor is the best bet for slowing weathering.

One system that is highly regarded by some experts -- and will retard weathering but probably not eliminate it -- uses products made by the Flood Co.

On new wood, a sealer called Seasonite should be applied soon after construction, and followed in a year by CWF-UV (clear wood finish with ultraviolet screen).

For more information on these products, call (800) 321-3444.

Q: We live in an old brick row house that is in good condition except for the front wall, which is bulging slightly. Where can I get the old-fashioned rods or spikes to help pull the wall back into shape?

A: I strongly recommend you have this project handled by an experienced contractor. Call masonry contractors in your area until you find one who is experienced with this procedure. I also suggest prompt action.

Readers' questions and comments should be sent to Gene Austin, c/o The Baltimore Sun, Box 8263, Philadelphia, Pa. 19101.

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