One of the big benefits of metal roofing is its low weight. More weight on the roof means your home is susceptible to buckling or snapping rafters. Worse, extra weight on the roof can be deadly in an earthquake or interior fire where the structure of the home loses its integrity and collapses under its own weight.
Composition (asphalt) shingles will tip the scales at 275 to 425 pounds per “square” (100 square feet) of roof while a tile roof can add up to 2000 pounds per square to your home. Steel and copper roofing will weigh around 85 to125 pounds per square. Aluminum will weigh even less at 45 to 70 pounds.
The low weight of metal roofing often allows it to be installed over existing shingles. In many cases, the temporary shingles have lost more weight in terms of evaporated oils and worn-away granules than what the new metal roof will add. Because of its low weight, metal roofing is often successfully installed over multiple layers of old shingles. This saves you money on costly tears offs that are “dumped” in landfills and pollute the ground water with its petroleum based chemicals.
However, in some areas, building codes prohibit more than two layers of roofing. Oftentimes though, by talking with the building inspector and explaining the low weight of metal roofing, metal has been approved for applications over 2, 3 or even 4 layers of old shingles. McCarthy Metal Roofing can help you in dealing with your local government officials with literature and documented history from past experiences.
For a sustainable, light weight roof for your home contact McCarthy Metal Roofing. We’re roofing experts that have teamed up with Classic Metal Roofing Systems to bring beautiful roofs to North Carolina.