At first glance, the days of wood home exteriors seem long gone. According to U.S. Census Bureau data, homes with wood siding comprise less than 10% of all new residential construction, the lowest usage of any exterior material.

But if you’ve got wood siding, there’s a solid, money-in-the-bank reason why you’d want to repaint rather than switch to fiber-cement, brick, or vinyl. In the short term, repainting or staining costs less. A midrange vinyl siding replacement project will cost you around $10,000, according to Remodeling Magazine’s Cost vs. Value report. By comparison, hiring a pro to repaint the same 2,000-square-foot, two-story house costs $4,000 to $6,000.

True, if you’re planning to stay in your house for a long time, you’ll have to spend that money again. But properly applied, exterior paint can easily last 10 years or longer. The key to a successful job is in the preparation. Here are the steps to take to make sure you get perfect results.

Step 1: Check for lead paint

Beginning April 22, 2010, all paint contractors must observe EPA regulations for lead-safe practices and be certified to perform this work. The rule applies to houses built before 1978, when lead paint was banned for residential use, especially those that are occupied by children. (Do-it-yourselfers are exempt.)

To protect against airborne lead particles, contractors must take steps to keep paint dust to a minimum: collecting scrapings, cleaning with a HEPA vacuum, wearing masks and Tyvek suits, and disposing of all materials at an approved hazardous materials site.

The first step is to initiate the process with a lead paint test (homeowner kits are available for $10 to $15 online or at paint and hardware stores). Following the new rules will add as much as 10% to 20% to the cost of a contracted paint job. But since many contractors are still unaware of the regulation, costs will vary widely.

Step 2: Wash the exterior

Pigment won’t adhere well if you don’t wash grime off the house first. A good cleaning agent is water mixed with a phosphate-free cleanser such as Jomax House Cleaner or Green Clean by Sherwin-Williams, which won’t harm plantings. “You want to clean off everything: dust, dirt, and mildew,” says Paul Dixon of Bionic Man Painting, in Asheville, N.C. “A lot of people don’t, and then wonder why the paint comes off.”

Mildew, in particular, thrives under fresh paint. A good wash will kill spores so they don’t proliferate. You can hand-apply the solution with a sponge, but that requires a lot of up-and-down on a ladder. Most contractors simply apply solution with a pressure washer.

Step 3: Scrape off loose paint

Once clapboards are dry, remove loose, flaking paint. A handheld scraper is usually the best tool for the job, though you can also use a hot-air gun or infrared paint stripper. Never use an open-flame torch. They can easily cause a fire and are illegal in most states unless you have a permit. To work lead-safe, you must wear a mask and Tyvek suit, spray water on the paint as you scrape, and collect the debris.

Step 4: Sand rough spots

A pad sander or random-orbit sander fitted with 50- to 80-grit sandpaper will smooth out any remaining rough spots, but take care not to push so hard that you leave sander marks in the wood. As with the previous step, sanding lead-safe means working masked, wetting as you go, and using sanders fitted with HEPA filters.

Step 5: Fill and repair

Inspect what you’ve uncovered and make some decisions. Minor holes or dings in the siding can be easily filled in with a patching putty or compound such as Zinsser’s Ready Patch ($20 per gallon). If you’ve got a major rot problem, summon a carpenter to replace the bad wood.

Step 6: Apply a coat of primer

Apply primer as soon as possible after the previous step. White, gray, or tinted primer provides an even base for topcoats to adhere to, and a uniform canvas from which to survey your work. “Once you get the primer on, now you can see what’s really going on,” says Mario Guertin, a contractor with Painting in Partnership, in Palatine, Ill.

Small gaps in joints and around doors, windows, and other spots where horizontals meet verticals will all stand out in high relief, showing you where you need to fill in with caulk.

If you’re painting over bare wood or existing latex paint, then latex primer is fine. But if you’re painting over multiple coats of oil-based paint, it’s best to stick with a new coat of oil-based primer.

Step 7: Caulk all joints

Siliconized or top-of-the line polyurethane acrylic caulks give paint jobs a smooth, pleasing look. But the benefits aren’t purely aesthetic. Tight joints also prevent air leaks and block water penetration. It’s worth springing for $7-a-tube polyurethane caulks with 55-year warranties, which will stand up to weather better than 35-year caulks costing less than $3. The average house requires about 7 tubes of caulk; contractors buy them in 12-pack cases and use them for several jobs.

Step 8: Choose the right paint

No-brainer here. Painting with water-based acrylic latex is so much easier than dealing with oil-based paints. But choose finishes carefully. As a rule, the higher the sheen, the better the paint is at blocking the sun’s damaging rays. Satin is fine for shingles or clapboards, but you’ll want gloss paint to protect high-traffic parts of a house, such as window casings, porches, and doorframes. A gallon of premium exterior latex costs $35 to $45.

Step 9: Apply top coat(s)

There is such a thing as too much paint. The more layers, the more likely the paint is to flake off years later. Tread lightly. If you’re going from a white house to yellow or cream, you might be able to get by with one coat. Going from a light to a dark house, and vice versa, usually requires two coats.

Step 10: Practice good maintenance

You can extend the life of a good paint job by inspecting the caulk every year, replacing any that’s cracked or missing, and doing minimal touch-up-all easy jobs for homeowners to do themselves.

Joseph D’Agnese is a journalist and book author who has written numerous articles on home improvement. He lives in North Carolina.