How to choose

Check our Ratings for a paint or stain (both available to subscribers) that resists the conditions that affect your house or deck. And buy paint in 5-gallon containers instead of 1-gallon cans, which can cut costs by up to 50 percent (figure on 12 to 25 gallons for a 2,500-square-foot house). Then keep these points in mind:

Insist on top finishes

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

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.

Look out for lead

Own a home built before 1978 and have children under 6? Federal law now requires that painters you hire be certified by the Environmental Protection Agency and be trained in lead-safe work practices. (Go to www.epa.gov/lead/pubs/rrpfactsheet2008.htm for more specifics.)