Metals used are mainly steel, aluminum, copper, and alloys, which are metals made up of two or more minerals. Steel is the most basic and can be the most affordable, although high end stainless steel roofs with their rust proof finish treated to weather beautifully, is more costly. Aluminum, which is coming down in price, offers a lightweight rust proof, durable roof. Copper is more expensive but is showy when installed and weathers to a beautifully distinctive shade; it, too, will not rust. The alloys, mainly steel mixed with other metals for rust resistance and strength, also are an expensive but alluring option.
In buying roofing, the heavier gauge and more expensive grades require a greater initial investment, which is regained as time goes by with low maintenance costs, improved performance in keeping out all sorts of weather, an increase in property values, more favorable insurance rates, and tax credits.
Metal roofs are extremely durable and come with extended warranties on materials. Steel will rust, but there are many baked enamel and other finishes that can be laid over steel to handle this problem. Steel and the other metals can also be shaped easily. A steel roof can be indistinguishable from clay tiles, cedar shakes, slate tiles, or asphalt shingles. The metal roof, while identical in appearance in color and texture, may be much lighter in weight. This can make it possible to lay a new roof over an older one without adding to the structural strength of the building.
These roofs, when properly installed, show great resistance to even tornado force winds, and shed snow easily. The metal does not draw lightening but rather offers increased protection to the structure, actually dispersing a striking bolt from its point of impact to spread the energy harmlessly over the whole roof. With proper attention to nails and flashing, a roof of this type can last as long as the building it shelters. The material is resistant to mildew, insects, fire, and rotting; it does not really deteriorate at all.
There are as many styles as there are color choices and material preferences. The traditional standing seam and the seam capped or batten roofs seen on old houses are still popular, but there are new styles as well. The seams can be high or low profile, or invisible to give a sheer, contemporary look. The sections, large or small can be crimped over-lapping or laid on in individual sections just like other shingles.
A metal roof is best left to professional installers, who know the stresses the roof will face over its twenty to eighty years life span. Proper attachments must be used that allow for the expansion and contraction of the metal, the sealer and flashing must be applied correctly, and the roof insulated (either with insulating materials or a dead air layer) and soundproofed if desired. Professional roofers will also offer a warranty on their work that may prove valuable if problems do occur.
Choosing metal roofing materials can be a very wise decision, whether in replacing a roof or in finishing a new construction project.