The Lofty Job of Roofing

At least once, most homeowners must replace a roof. If you think you might need a new one, here are several things to consider.

The average roof will last 15 to 25 years, so it’s best to take a look at your roof when it’s close to 15 years old. Specifically, check for curled, cracked, discolored or missing shingles. You’ll also want to look for spots where surface granules have worn off the shingles. The flashing—those metal plates that seal out water around chimneys, dormers, roof valleys and vent pipes—also may be damaged.

Check the attic, too. From there, you can see signs of rotting on the roof deck. And during a rainstorm, you can tell if the roof has leaks.

When you decide it’s time to replace the roof, you’ll also need to decide whether to place the new shingles over the old ones or to remove the old shingles first. This second choice is called a "tear off," and some local building codes require it when there are already two layers of shingles.

Roofing is hard, heavy and hot work. An experienced roofer spends up to 40 hours on a one-story house, and it might take you twice as long to do it yourself. Unless your home is a single-story, ranch-style house with a roof that isn’t too steeply pitched, it can be very dangerous work. You’re probably better off choosing a contractor.

Begin by talking to the people you know who’ve had roofing done recently. Or contact your local chapter of the National Association of the Remodeling Industry for references. Then get at least three estimates. Although cost is important, use the work each proposes to do for the money to make your comparison. Keep in mind that a contractor’s price generally is about 60 percent labor and overhead and 40 percent materials.

The cost of roofing materials is determined by weight and life expectancy. Weight is measured per spare, and a square of shingles covers 100 square feet of roof. The average home needs about 20 squares. Life expectancy is the length of the manufacturer’s guarantee.

Asphalt shingles, the most commonly used roofing material, come in three price ranges. The more expensive, the heavier they are and the longer the guarantee. Laminated fiberglass-asphalt shingles often are designed to look like wood shingles and come with warranties of up to 40 years.