Hidden substructure damage often turns a repair job into a full-blown makeover.

The deck's far from new, but the client's only interested in having some boards replaced. What now?

Rick Parish, of Decks Appeal, Dallas, looks at the substructure. If that's starting to go, replacement is his first suggestion. "If they want me to put a thousand-dollar Band-Aid on, and it means spending another thousand the next year, I'll be up-front with them and say that the deck's seen better days." In the Dallas market, Parish points out, 15 years is a typical life span for a pressure-treated pine deck.

Low resistance

Suggestions that the deck be replaced rather than repaired rarely meet with resistance, Parish says, especially if he can point to substructure damage. In the San Francisco Bay area, Gary Marsh, owner of All Decked Out, agrees that crumbling substructure is the determining factor. "It's foolish to put money into repairs if the joists are 20- to 30-year-old untreated Douglas fir," he points out.

Naturally such news is not welcome to clients who hadn't banked on a new deck. But Marsh leavens the bad news by pointing out that he can design a deck -- of any size, in any material -- that will last 40 or 50 years. "Using the correct pressure-treated wood, stainless steel fasteners, and sealing all potential [water] penetrations," he says, can go far in extending the life of the deck.

High maintenance

For Tom Resek, owner of Archadeck of Minneapolis, maintenance issues are often paramount. Typically, deck owners put maintenance work into the structure three or four times, then lose interest, which contributes to the rate of deterioration.

"The obvious thing is if the deck boards look worn," he says. "If the deck boards are rotten, you don't know what the joists are going to look like." Other repair issues that point the way to replacement include weak or loose railings, code violations, and poor initial design or construction. Resek says he replaces 65% to 70% of wood decks with composite materials. When a possible repair job becomes a replacement, 90% of clients use composites, which require minimal maintenance.

The value of maintenance in extending the life of a deck varies with local weather conditions, but one thing that doesn't vary is that the older the deck, the less interested the homeowner seems in maintaining it. "It's like a car," Parish notes. "You wash it a lot less after five or six years."