To find out which finishes are likely to last longest on your home, we painted and stained pine test panels and placed them on the roof of our Yonkers, New York, headquarters. We faced the boards south at 25 degrees from vertical to intensify the effects of sun and weather. One year of such severe testing is equivalent to about three years of normal weathering on a typical home. Most exterior paints held up well for the equivalent of at least three years, and the best still looked fine after what amounted to nine years under the elements. Stains must typically be reapplied more often--some after as little as one year.
As with interior paints, manufacturers typically reformulate exterior paints and stains often, partly to meet tougher federal standards limiting volatile organic compounds. VOCs can cause headaches and dizziness, and are linked to pollution, smog, and respiratory problems. Reducing VOCs in exterior paint without compromising performance had been a challenge, but now many low-VOC paints top our Ratings. Whether you paint or stain, here are some tips for getting the best-looking, most durable finish possible:
Skip the cheapest paints. As with interior paints, we've found that economy grades of paints and stains don't weather as well as top-of-the-line products from the same brand. Pinching pennies now may mean spending more down the road, since you'll need to refinish more often.
Choose the right gloss level. Flat and satin finishes are best for siding because they hide flaws by reducing reflections. Semi-gloss paints add some shine to doors and trim, providing visual contrast.
Insist on top finishes. Hiring a pro? Be sure the contract specifies the brand, line, and number of coats; for paint we generally recommend two top coats plus a prime coat over bare surfaces if paint is not self-priming.
Look for deals. Holiday weekends, including Memorial Day and the Fourth of July, are popular times for paint promos.
Don't scrimp on the prep work. Good preparation is critical to a good, long-lasting exterior finish, whether you're paying a pro or are doing it yourself. That means scraping, sanding, and cleaning the siding thoroughly. And while the best paints cover in one coat--and many claim to eliminate the need to prime the surface--we recommend two coats for long life and optimal coverage. Other materials may require different procedures. Stucco and masonry, for example, may need sealing beforehand. If you sand or scrape paint on a house built before 1978, be warned: Older coats of paint may contain lead, so you'll need to take extra precautions. Indeed, federal law now requires that painters you hire be certified by the Environmental Protection Agency and be trained in lead-safe work practices.