A harsh winter has taken a toll on many roofs. Maybe there's a tell-tale leak, but sometimes problems are harder to spot. Now that the snow has melted, it's a good time to take stock.

Identifying problems

John Galeotafiore, associate director of home improvement testing for Consumer Reports, recommends that homeowners take out a pair of binoculars and check the roof from street level.

Do you see any missing shingles? Are some of them curled or cracked? Are there pieces of flashing missing? Dirty or splotchy shingles also can be a sign of a problem, says Jim Englehart, senior merchant for building materials at Home Depot. "It's indicative of the granules being worn away," he said.

Repair or replace?

Age is one factor in deciding whether to repair or replace a roof.

"If the roof is about 20 years old and you're getting leaks, you're probably going to have to change it," Englehart said.

You might be able to patch newer roofs if the damage is limited.

"It gets down to aesthetics," Englehart said. "If it's on the front side of the house I don't want to patch. The patch is going to be a different color."

Sometimes, new shingles can be layered over an existing asphalt roof, saving some labor costs. But no more than two layers total is advised, in part because of the added weight on the home.

Roof types

Most homes in the United States have a pitched roof. Asphalt shingles make up a large share of the market, but some roofs are slate, metal or a composite material. Wood shakes and tile also are used.

And then there's geography. "Different kinds of material will perform better in different climates," said Bill Good, executive vice president of the National Roofing Contractors Association.

In the Midwest, he said, a lot of asphalt shingle is used. Asphalt shingles come in two main types: three-tab shingles, which are a single layer, or laminated or architectural shingles, which are thicker.

Metal roofs range from steel to copper and other materials, either in panels or in shingles similar in size to asphalt shingles. Good said they last a long time, and "also tend to be reflective, so they can help with energy conservation inside the home."

As for cost, asphalt is generally the lowest among roofing options. Slate and copper roofs, for example, can be much costlier.

Picking a contractor

Good recommends talking to two or three contractors before deciding on one. Besides comparing prices and warranties, check that the company is insured and has a permanent place of business. It's also good practice to ask for references, Good said.