New roofing: How many years can it last?

If you are considering re-roofing your home, your investment in roofing materials has a direct correlation to how long you can expect your new roof to last. The longest-lasting roofing products are inherently extremely durable, such as concrete, clay or slate tiles and significantly outperform other natural products like wood shakes. Manufactured roofing materials -- asphalt shingles, metal roofing -- have a good lifespan but are not as durable.

It's also important to keep in mind that regional weather conditions, the design of your building, amount of routine maintenance and the quality of the roofing products you purchase play crucial roles in determining the life expectancy of roofing materials.

New roofing: How long do products last?

According to the National Association of Home Builders, most roofing products are designed to last a minimum of several decades under normal weather conditions. Here's a closer look at how the NAHB rates the longevity of different roofing materials:

• Asphalt shingles -- Typically, asphalt shingles last about 20 years; however, higher-quality asphalt shingles are warrantied for up to 50 years. Expect to pay more for a premium, long-life product.
• Architectural asphalt -- These products last about 30 years on average.
• Wood shingles and shakes -- Wood roofing has a target lifetime of 30 years, but it can last much longer under moderate weather conditions.
• Metal -- The International Association of Certified Home Inspectors projects metal roofing to last between 40 to 80 years. The Metal Roofing Alliance gives a life expectancy of at least 40 to 60 years.
• Slate, concrete and clay tiles -- Each of these products is rated for a life expectancy of 100 years or more by both the NAHB and NACHI.

Roofing costs

Longevity in a large part is related to the cost and style of roofing materials.

Asphalt shingles, which start around $.80 a square foot, are among the least-expensive residential roofing products. Difficulty of installation can greatly increase the cost per square foot, though. Architectural shingles, which are usually about twice as thick (and heavy) as asphalt costs approximately twice as much as regular asphalt shingles.

Metal roofing materials are a premium home product, the Metal Roofing Alliance says, and costs run about two to three times that of asphalt shingles. It's comparable to tile or cedar shakes, but less expensive than slate. Expect to pay between $3.50 to as much as $11 per square foot, says New England Metal Roof company. Adding a breathable underlayment can boost these figures as well.

The Durable Slate Company, which has offices across the Eastern U.S., says simple roofing designs cost about $15 per square foot, but more complicated framing designs and premium slate roofing materials can cost as much as $40 per square foot.

Pros and cons of different roofing materials

Asphalt shingles are the most widely used roofing product in the U.S., the National Roofing Contractors Association says.They are relatively inexpensive, and there is a tremendous array of colors, patterns and styles from which to choose.

Architectural asphalt shingles are a relatively new product. Companies such as CertainTeed have introduced a material made from engineered polymer composites that imitates the look of cedar wood shakes or slate tiles. The good news is that they are much less expensive than natural products; the drawback is that they lack a history of performance statistics.

Metal roofing materials, which include metal shingles, slates, tiles and vertical panels, weigh about half as much as asphalt shingles and are 75 percent lighter than tiles. Problems are the same as with other materials: leaks, punctures or tears and pooling water.

Wood shakes that constantly become wet in the winter typically become so warped from a lifetime of wetting and drying with the seasons that they jeopardize the integrity of the roof. They still are a popular choice in many parts of the country, though. The Cedar Shake and Shingle Bureau says pressure-treated shakes hold up better, and that thick-cut cedar shakes generally last longer than thinner cedar shingles.

The main drawback with slate roofing is weight. Slates 3/8-inches thick weigh as much as 1,500 pounds per square (a 10-foot by 10-foot area), and each additional 1/8-inch thickness increases the weight by 500 pounds per square.

Before choosing a type of new roof, consider how much you want to pay, what kinds of roofing products are used in the neighborhood surrounding your home, and how long you expect to be in your home. You also might want to consult with a roofing contractor about which materials are the best fit for your geographical region.