Dear Jim: I want to install a metal roof with a lifetime warranty, but I worry it will make my house hotter and increase my air-conditioning bills. Does the long life of a metal roof offset such disadvantages? – Regina H.

Dear Regina: You must have talked with an asphalt-shingle salesman. Actually, installing a metal roof can lower your air-conditioning costs and improve your comfort. Also, since you will never have to install a roof again, the life-cycle cost of a metal roof is reasonable as compared to other materials.

Metal roofs are becoming a signature of expensive, top-end home builders. They cost more to install than shingle roofs, but the difference is not as great when reroofing. Metal roofs can be applied over several layers of old shingles, so the tear-off expenses are eliminated. If you like a tile or slate look, the lighter-weight metal will not require roof reinforcement.

The Florida Solar Energy Center built test homes with various roofs. In 90-degree weather, the attic temperature with a simulated cedar shake aluminum roof was almost 30 degrees cooler than one with asphalt shingles. This can result in 33 percent less of a cooling load on your central air conditioner.

Another major advantage of metal roofs is they are fireproof. Fires are often spread from house to house by glowing embers carried by the wind. If embers settle on a metal roof, they will not start a fire. Houses with metal roofs may receive a discount on the homeowner’s insurance.

The two most common metal roofing materials are painted aluminum (recycled from beverage cans) and steel. Both are strong enough to handle the weight of a person carefully walking on the roof. Copper and stainless steel are durable, but their cost is often outside of the budget of many homeowners.

Aluminum is an excellent material because it is easily formed to perfectly simulate cedar shakes, tiles and slate. Aluminum does not rust, so if there is an imperfection in the paint or it gets scratched, durability is not affected. The irregular surface eliminates noise from raindrops.

Simulated cedar shakes are most popular and are difficult to distinguish from real shakes. They are formed in multishingle panels to install quickly and they interlock to eliminate leaks and high-wind blow off. Many standard colors are available and some use energy-saving (heat barrier) paint.

Most steel roofing is painted with tough Kynar as is aluminum. For the most authentic appearance, some include real stone granules in the final coat (10-coat process). Powder-coated Kynar, applied after the panels are formed, is most durable and attractive. Standing seam roofing is ideal on contemporary homes and simulated tiles create a Western-style appearance.

Write for (instantly download – www.dulley.com) Update Bulletin No. 896 – buyer’s guide of 17 manufacturers of residential aluminum, copper, steel roofing listing styles, colors, finishes, weights, features and installation details. Include $3 and a business-size SASE, and send to James Dulley, 6906 Royalgreen Drive, Cincinnati, OH 45244.