Paints & stains: the test of time.(Outdoor Living)

Just about any exterior paint or stain will make your house look good for a few years. But the best products on the market can maintain their looks for as many as nine years, according to our ongoing tests. Choosing a product that performed well for us can help you save thousands of dollars by extending the life of your paint job.

Unfortunately, you can't simply stock up on the brand you favored in the past. Manufacturers regularly reformulate their products to improve performance, cut costs, or comply with environmental regulations.

As the Ratings on the next two pages show, products from three leading brands--Sherwin-Williams (the biggest), Behr (sold at Home Depot), and Sears-have been reformulated. The products now in stores may not perform exactly like their counterparts in the Ratings. We'll be testing the new versions once they reach stores. Product changes also explain the absence of Dutch Boy and Benjamin Moore from this year's Ratings.

Our Ratings are based on accelerated weathering tests, using white, blue, and brown paints and white, red, and green stains, Those colors represent not only widely used house colors but also broad families of hues and different types of pigments, which react to weathering in different ways.

We brush two coats of each paint onto primed sections of wood siding; two coats of stain go on unprimed wood. We leave them all outdoors on racks that we angle to catch the most sun. Each year for three years, we evaluate the painted and stained boards to judge how much their appearance has deteriorated, since a year of that kind of severe exposure is equivalent to about three years of normal exposure to the extremes of sun, rain, wind, and temperature.

HOW TO CHOOSE

Paint or stain? A house that's been stained can always be painted, but the reverse isn't true. Few homeowners are likely to scrape off layers of paint to switch to stain.