Deck treatments: long-lived colors.(Product/Service Evaluation)

Opaque and semitransparent deck finishes used to come in a very small selection of colors, most of which had all the pizzazz of battleship gray. Today, manufacturers offer dozens of off-the-shelf premixed shades as well as colors mixed at the store.

Also in recent years, manufacturers have reformulated many opaque and semitransparent treatments, especially to improve their ability to fend off dirt and mildew We'd like to think that's a response to previous findings from our six-year testing program to determine how well the leading deck treatments hold up to the elements. The details:

Opaques rule. One opaque treatment the Cabot Decking Stain, has outperformed all others in its third year of our ongoing tests. Besides resisting mildew, it has proven the best at keeping its original color. Several other opaque finishes are in their first year or two of testing and look promising so far.

Other deck finishes rarely last. One Wolman semitransparent and one Olympic clear finish still look good after three years. But most clear finishes haven't resisted dirt buildup or mildew. The also were away, exposing the wood to moisture.

HOW TO CHOOSE

Consider the wood. If your deck is made of pressure-treated pine, the most common material, an opaque treatment is the best choice (see First Things First, below). Not only does an opaque treatment last the longest, saving you money on materials and a few weekends of time, it also lets you have a deck finish that complements the color of the house.

If you've chosen cedar, redwood, or a similarly showy and expensive wood for the deck, you'll probably prefer a finish that reveals the wood's natural grain. A semitransparent treatment is usually a better choice, since it allows the wood grain to show while providing more protection for a longer period of time than most clear treatments.