Metal Roofing Benefits
Metal beats out conventional roofing materials on a number of different counts:
Expected life. Properly installed, a metal roof should last as long as the house, sealing out water, surviving high winds, and easily shedding snow. Metal is resistant to fire, mildew, insects, and rot. Warranties vary widely, but most companies back their products for 20 to 50 years. Paint finishes typically have a 30-year limited warranty.
Weight. Compared with tile at 750 pounds per square (an area equal to 100 square feet) or concrete tile at 900 pounds per square, metal roofing is lightweight. Most varieties run from 50 to 150 pounds per square.
Sheet-metal roofing is lightweight, fire-resistant, quick to install, and great at shedding water and snow.
Some types of metal roofing materials may be applied over an existing roof without the need for tear-off or additional structural support. In fact, if you’re building a house or an addition, you can often downsize or reduce the number of roof support members.
Speed & ease of roofing installation.Most metal roofing materials come in multiple-shingle sections or in 12- to 36-inch-wide panels. An accomplished contractor can install these quickly. If your roof is stripped off and a storm is on the way, shortening the process by a day or two may prove to be a critical advantage. Because of the material’s light weight, you can save on engineering and building the supporting structure.
Fire resistance. Because metal roofs are noncombustible, they’re given a Class A fire rating (the most resistant). Part of a roof’s classification depends on materials beneath the surface that could ignite in intense heat. Most metal roofs applied over a combustible material such as wood shingles have a lower, Class C rating.
Heat conduction. Metal reflects radiant heat from the sun, minimizing midday heat gain. This means you save energy needed for air conditioning during the day. Though the material itself is low in insulation R-value, many systems utilize a dead-air space between the metal and roof deck to increase energy efficiency.
Minimal roof pitch. Most metal roofing materials can be installed on gently pitched roofs without presenting a leaking potential. Minimum roof pitch is 3-in-12 (the roof rises 3 inches for each horizontal foot).
Maximum shedding of rain and snow. Metal roofing is practically impervious to rain and snow because of the way it is designed to interlock and because the surfaces are hard and slippery.