Wood stain buying guide

Wood stains must meet new environmental rules that lower volatile organic compounds. VOCs can cause acute symptoms such as headaches and dizziness, and some may be carcinogenic. But manufacturers admit that removing VOCs from wood stains and treatments without reducing performance is a challenge. Wood stains that made our winners list still looked good after the equivalent of up to three years on a deck. All of our picks meet or beat federal limits for VOCs of 350 to 550 grams per liter for stain. Several also meet stricter regional California limits of 100 grams per liter for stain. Some offer mildew resistance.

Before 2004, most decks were made of lumber pressure-treated with chromated copper arsenate to fend off rot and insects. But concerns that arsenic, a toxin, could leach into the soil led to the introduction of other preservatives. If the wood in your deck is pressure-treated with CCA, the U.S. Environmental Protection Agency recommends using a semitransparent stain, which tends to penetrate the wood and seal in the arsenic, preventing it from leaching out. Opaque treatments also seal well, but they may flake or peel and require sanding, which would spread arsenic-laden dust from CCA lumber. If your deck is made of CCA lumber and its finish is flaking, we suggest calling a pro equipped to safely remove the old finish, dust, and debris.

Wood stains that made our winners list still looked good after the equivalent of upto three years on a deck. All of our picks meet or beat federal limits for volatile organic compounds (VOCs) of 350 to 550 grams per liter for stain. Several also meet stricter regional California limits of 100 grams per liter for stain. Some offer mildew resistance.

Insist on top finishes. Your painter's favorite stain might not be a top pick in our tests. The contract should specify the brand and line of stain, its cost, and how many coats the pro plans to apply. (Figure on a coat or two.)

Prep decks carefully. Washing and sanding are typical first steps to staining a deck. But sanding a wood deck treated with chromated copper arsenate (CCA) releases toxic arsenic into the air and surrounding soil. Call a pro if your deck was built before 2004 and its finish is flaking.

Also known as solid-color stains, opaque treatments typically hold up for at least three years--the longest overall. They're fine for pine decks, where seeing the grain isn't important. On the downside, they hide the wood grain the way paint does. Opaque finishes might also build up a film, especially after several coats, which can peel, chip, and crack like paint. That's a concern with older decks made of arsenic-laden, CCA lumber.

Although generally not as weather-resistant as opaque treatments, some semitransparent products go the distance better than others. Semitransparent products let some of the wood grain show through, making them a good choice for cedar, redwood, and other costly woods that you want to show off. But they range from little pigment to nearly opaque. And even the best we tested needed refinishing after two years.

These may contain only a little pigment, along with water repellants. They're ideal for showing off the natural grain of a premium wood as much as possible. Clear treatments may have ultraviolet inhibitors and wood preservatives. But with most, deck refinishing is an annual chore.

Latex-based stains and treatments allow easy cleanup with water.

Most alkyd (oil based) products require cleaning with mineral spirits, though a few can be cleaned with water.

Behr is a leading brand of exterior coatings and is available exclusively at The Home Depot. For decks, Behr offers solid, semi-transparent, wood-toned, and clear finishes.

Benjamin Moore makes a wide variety of decking stains, including water and alkyd-based solid, semi-transparent, wood-tone, and clear finishes. Benjamin Moore operates over 1,200 Benjamin Moore paint stores and has about 4,000 independent dealers who carry the brand; The company cites training and service as reasons why it hasn't entered the home-center channel.

While Valspar does not make deck treatments, its acquisition of Cabot has certainly propelled it to the top of the category. While many brands offer combined deck and siding stains, Cabot makes alkyd and latex-based solid, semi-transparent, and transparent stains tailored for each application. Cabot has also introduced stain for composite decking.

Olympic is a member of PPG's architectural coatings family of brands (the company was formerly known as the Pittsburgh Plate Glass Company). Olympic exterior stain can be found at Lowe's and independent paint and hardware dealers. Olympic stains include solid, semi-transparent, wood-toned, and clear finishes. Its most popular stains combine deck, fence, and siding applications in one product.

Sherwin-Williams is the largest producer of paints in the United States. Sherwin-Williams manufactures deck treatments under the Deckscapes line, which is sold at more than 3,000 company-owned retail stores. Its retail stores cater to professionals and consumers, and offer a variety of paint supplies and tools.

With an effective advertising campaign that includes television spots over the last decade or two, Thompson's WaterSeal has become a recognizable brand leader in deck treatments. Thompson's signature product is a clear waterproofing finish, and the company has expanded its line to include oil and latex stains. Thompson's is available nationally through home centers and major retailers such as Walmart.

While Valspar does not make deck treatments, its acquisition of Cabot has certainly propelled it to the top of the category. While many brands offer combined deck and siding stains, Cabot makes alkyd and latex-based solid, semi-transparent, and transparent stains tailored for each application. Cabot has also introduced stain for composite decking.