DEAR SALLY: Tin metal roofing was immensely popular in the late 1800's and early 1900's. Labor was inexpensive at that time and there was an abundance of craftsmen who could easily install the material. Metal roofing systems are still available and great strides have been taken to simplify their installation. Metal roofing also has a history of proven performance. Simple flat seam metal roofs have been found in buildings dated to 3,000 B.C.

Metal roofing is a superb material for residential buildings. If you choose the right system, you can get a roof that will easily last your lifetime and quite possible an additional 50 years or so. Expect to pay for this performance, however. Metal roofing is pricey. A metal roof can cost at least three to four times what you might expect to pay for a high quality asphalt shingle installation.

There are numerous advantages to using metal roofing. First of all, it is totally fireproof. If you live in an area that experiences wildfires, a metal roof just might save your home from a devastating roof fire caused by a wind blown ember. Metal roofs are made with environmentally friendly recyclable metals, such as steel, tin, aluminum and copper. A house with a metal roof can be extremely distinctive. When installed correctly, metal roofs are extremely wind resistant. A light colored metal roof can actually reflect a portion of the sun's radiant energy, thus lowering your cooling costs.

Aside from the traditional standing seam look, you can also install flat lock metal roofs and ones that look like traditional overlapping shingle type or Spanish clay tile roofs. Certain manufacturers have gone so far as to coat the metal roofing shingles with colored ceramic granules to simulate the look of asphalt shingles!

Don't hesitate to select a painted metal roof product. This is especially true if the paint has been treated with a clear fluoropolymer resin. This coating was originally used to inhibit corrosion on the inside of steel piping used in chemical plants. Fortunately someone decided to try it on top of paint to stop ultraviolet (UV) degradation and fading of colored paints. It works so well that painted roofs can retain 85 percent of their original color after 20 years of exposure.

If you decide to purchase a metal roof system, make sure that the installer uses all matching components during the installation. In other words, all assembly parts must come from the same metal roof manufacturer. Pay particular attention to instructions with respect to ventilation. Metal roof failures can happen and often the corrosion begins on the underside of the roofing. Condensation can form under some metal roofs. You need to make sure that the underside of your metal roof can breathe readily and dissipate the condensate water and water vapor.

Be sure your roofer follows written installation instructions to the letter. If you live in a high wind area, pay attention that the bottom and top edges of the roof are installed correctly. These areas of the roof receive the highest loads during sustained wind storms. Most metal roofs need to expand and contract readily. Special metal clips and fastening techniques are employed that allow the roof to move yet remain watertight. Be sure you hire a roofer that understands this vital concept.