Metal Roofs Versus Other Roof Materials
You’ll be surprised to learn that a metal roof is, on average, 50% lighter than an asphalt shingle roof, and 75% lighter than concrete tile, fiber cement shakes and slate. With metal roofing, weight on a structure is never an issue. And in cases where metal may be installed over an existing roof, it may be the only practical answer because other materials may add too much weight load for the existing roof to bear.
Standing seam metal roof systems in most cases weigh between 1 to 3 pounds per square foot. The actual weight is dependent upon metal gauge and profile of the panel. Nonetheless, metal roof systems are considered a lightweight roof covering compared to their counterparts. The following illustrates the different types of other roofing materials and their respective weights per square foot:
- Asphalt Shingle: 2 – 3.5 pounds per square foot
- Textured Asphalt Shingle: 3.5 – 5 pounds per square foot
- Wood Shingles/Shakes: 3.5 – 4.5 pounds per square foot
- Clay or Concrete Tile: 5.5 – 10 pounds per square foot
Steel standing seam will weigh about 85 – 120 pounds per 100 square feet of roof area. Aluminum standing seam weighs about 70 pounds per 100 square feet. In contrast, asphalt shingles weigh from 275 – 425 pounds per 100 square feet.
Because standing seam metal roofing material is so light, some building owners assume you shouldn’t walk on it. Absolutely not true. The truth is that you can safely walk on any metal roof applied over plywood or metal sheathing without damaging it. But before you do, check with your metal roofing installer or the manufacturer of your metal roofing material (ask your contractor) for instructions for your specific roof. And of course, if you are walking on a roof, be careful!