If you're like most companies that build decks, the moment the last nail or bolt is attached is the last time you see the product. Most remodeling companies don't bother with deck maintenance for a number of reasons. It's a seasonal business. The jobs are small, priced at somewhere between a dollar and two dollars per square foot, which usually comes to less than a thousand dollars for a two-man crew to wash and stain. Carpenters have little enthusiasm for it. Margins are not lucrative.

"I just don't go down that path," says Randy Varga, owner of Decking Northwest in Portland, Ore. "There is so much work for us to be had in selling and building decks."

Tom Jakes, whose Hickery Dickery Decks in Ontario, Canada, has built 4,000 units in the past 15 years, offers maintenance contracts but doesn't encourage them. Like many deck builders, he subs out maintenance to local painting contractors. If painters can't squeeze in the job, Jakes uses the college student who works for his company in the summers to fulfill deck maintenance contracts. The deck maintenance business, he says, is a headache.

Still, demand for maintenance services is big, and getting bigger. Treatment minimizes repair and enhances deck aesthetics. Specialized deck cleaning companies and deck maintenance franchises, such as Deckshield, have sprung up, most of them operated by painters. Steve Erps, whose Deck Detail in Plymouth, Mich., has sold more than 200 deck maintenance contracts to suburban Detroit residents in the past two years, says his clients have neither the time nor the expertise to maintain their decks.

Cameron Bagherpour, owner of Building Magic, a full-service remodeling company in Homewood, Ill., started offering deck maintenance services to clients three years ago. The reason? "Overwhelming numbers of requests," Bagherpour says.

To handle those, Bagherpour had the two carpenters and three laborers on his staff trained in deck maintenance, which involves pressure washing and then applying sealant to the wood. "A lot of carpenters don't want to do painting," Bagherpour says, "but my guys are happy to do it."

Maintenance now accounts for about 10% of the company's deck volume, and building decks is half its business. Bagherpour says margins are less on deck maintenance. "On any kind of construction the profit margin will increase as the perceived level of expertise required to do it goes up," he says. But maintaining decks for clients, and now for non-clients as well, helps bring in new deck jobs. When people see a well-maintained deck, they want to know who built it. So the company includes the offer of every-other-year maintenance as part of its sales presentation. Maintenance, says Bagherpour, is a "really good upsell."

Though deck maintenance is a growing business, some in the deck construction industry wonder if it's a service whose days are numbered due to the increased popularity of low-to-no-maintenance composite and vinyl decks.

Mike Owens, executive director of the Plano, Texas-based Deck Industry Association, predicts composites will minimize the need for deck maintenance in the years ahead. "More and more companies are going to composites," he says. "Which means there'll be less and less need for maintenance down the road." But those who maintain decks see a good 30 or 40 years, at least, before composites overtake wood.