Whether you're putting a roof on a new home, or your existing roof requires a total makeover, there are many materials available. But no matter what roof style you have, metal roofs can be an attractive option because of their longevity, minimal maintenance and energy efficiency. Material choices include steel (galvanized, galvalume or weathering), aluminum, copper, zinc and tin. Product types are vertical seam, pre-formed panels and granular coated panels. Style choices allow you to have the look of shingles, slate, tile, shakes or vertical panels. Make sure your metal roofing product is tested, labeled and listed with a testing organization such as UL, FM Approvals or Intertek to meet rigorous wind, fire and impact resistance rating requirements. Please also remember that installation can vary from geographic location, manufacturer guidelines and as a result of local building code requirements.
Advantages of metal roofs
Metal roofs offer many benefits, including:
- Longevity. Metal roofs can last 40-70 years, depending on the material. Traditional asphalt roofing materials have an estimated life expectancy of roughly 12-20 years.
- Durability. If installed correctly, some metal roofs can sustain wind gusts up to 140 miles per hour, will not corrode or crack and may be impact-resistant (depending on which product you choose). In addition, metal roofs don't need the periodic costly maintenance that other roofing materials often require. However, they should be inspected periodically to make sure no repairs are required.
- Safety. Metal roofs will not spark and ignite into flames during a wildfire or lightning strike.
- Energy efficiency. Metal roofs reflect the suns UV and infrared light rays that contribute to roof surface radiant heat, which can result in a 10-25% reduction in cooling costs.
- Environmentally friendly. Metal roofs not only have 25-95% recycled content, depending on the material used, but are also 100% recyclable at the end of their life as a roof. In contrast, most shingle tear-off waste ends up as part of the building-related waste stream — up to 20 billion pounds per year.
Disadvantages of metal roofs
Despite their many advantages, metal roofs have some potential drawbacks.
- Affordability. Metal roofs can be as much as two or three times more expensive than other roofing materials. While the life of a metal roof is much longer, investing in a metal roof only makes sense if you plan to stay in your home long enough to enjoy the cost benefits.
- Noisiness. Metal roofs may be more noisy during a heavy rain or hailstorm than other products depending on the type of decking used during installation (spaced or solid). Adding more attic insulation can sometimes solve this problem, but that may increase costs.
- Expansion, contraction and fasteners. Metal roofing material assemblies that are attached as large panels are designed to expand and contract as they warm and cool. However, both exposed and concealed fasteners have varying lifespans. Depending on the climate, neoprene washers and the screws used during installation may degrade and become dislodged over time.
- Inconsistency of color match. If a repair is required or a home extension is added years later, it may be difficult to find an exact match to the existing metal.
- Performance. If water accumulates anywhere on the roof because of poor-quality installation or repair, it can eventually cause serious damage. Low-grade metals may also be thinner gauge and less durable. Some metals rust in certain climates or dent more easily than others during hailstorms or installation.