One of the greatest benefits of a metal roof is its durability. Nothing beats a steel roof for longevity. How long does a metal roof really last though?
Age vs. cost
A metal roof is typically warrantied for up to 40 years, already a longer period than a similar traditional roof. The Metal Construction Association has found metal roofs that have been around for 60 years or more.
Compare that to about 23 years for an asphalt shingle roof and 20 years for a single-ply roof. Double the lifespan is pretty impressive but doesn’t really address the biggest concern: cost.
A Ducker Research Company survey showed that the lifecycle cost of a metal roof averaged about 30 cents per square foot. Going back to the comparison with asphalt and single-ply, Ducker found the lifecycle costs for those materials to be 37 cents and 57 cents per square foot respectively.
Going even further, the survey determined that a metal roof cost 3.5% of the total installed cost while asphalt was 38.5% of the total cost and single-ply was about 19%.
Just knowing how long something lasts isn’t enough. You also need to know the difference in costs.
Why does metal roofing have a long life?
As we stated before, metal is a durable material, but durability on its own cannot account for longevity. A metal roof is more than a series of steel panels; it is an entire system made up of clips and framing members that all impact how long the roof will last.
Roof clips securely hold the roof panels to the structural members but leave enough “wiggle room” for the panels to move with the expansion and contraction caused by the temperature changes each day and from season to season.
Further improvements to durability include sealants at the seams and heavy duty fasteners. Factory punching ensures the panels properly align and mitigates the danger of corrosion at the edges of the holes. Splices are staggered to prevent completely exposed seams and leak points. Roof curbs and openings are also factory engineered, and the fasteners are concealed inside the curbs to eliminate the potential for leaks.
Other reasons for durability
Metal is resistant to the environment, more so than asphalt and other traditional roofing materials. It can withstand high winds and other severe weather that would tear an asphalt roof apart. Metal is also resistant to impact, so even a hail storm does not necessarily lead to a new roof.
Metal is also resistant to fire. If lightning strikes a home with a metal roof, there is little chance that the house will burn. The electrical charge is spread over the roof. At the point of contact, the metal is more than able to withstand the heat of the lightning bolt.
Metal is also resistant to seismic activity, with the roof clips allowing movement just as they do for temperature changes. The metal may buckle, but it will not splinter or shatter.
One final reason a metal roof lasts so long is that, so far, there aren’t any pests that can eat it.
Environmental impact of steel roofing
Metal is highly sustainable. Most of the steel available today has a high portion of recycled steel within it. If and when the metal must be removed, it can be 100% recycled, whereas asphalt shingles would be headed to a landfill.
Besides being completely recyclable, a durable roof is not replaced as often, mitigating fuel usage and pollution from heavy equipment.
Sustainable metal roofs coated with light colors have high reflectivity and emissivity ratings, two ways a metal roof conserves energy. When heat is reflected away from a building, less effort is required of the air conditioning units, while heat reflected back into the building instead of being transferred outside keeps things nice and toasty without a high heating bill.
Metal roofs can be insulated more heavily than a traditional roof, another way to keep the indoor environment comfortable. Solar panels are easily mounted as are special skylights that can gather more light than typical flat skylights. Such a system requires fewer roof penetrations and reduces the amount of cut edge exposed to a corrosive environment.
Other benefits of metal roofs
Beyond the long life and sustainability, steel roofs can improve your property value and save on insurance. Because it is durable in weather and fire resistant, insurance companies consider a metal roof a better risk and charge lower premiums.
Additionally, metal roofing materials can be created to look like any other material in any color or texture.
Ensure a long life for your metal roof
Metal roofs need little maintenance but each year you should clean off the dirt and debris, so there is no place for water to accumulate. Inspect all the fasteners for corrosion and replace any that need to be. Make sure all the flashing is in good shape around the roof penetrations and take care of any scratches and dents by repainting when necessary.
Yep, a metal roof can last a long, long time if it is installed and maintained properly. Not only that, but it will cost you less in the long run. Add the right flashing at penetration points and other areas of the roof along with the appropriate maintenance and you will have your 40-year roof.
Considering the cost of replacing a roof every 20 years, less if the roof is destroyed by a hailstorm, the higher initial cost of a metal roof earns a return on investment that you won’t see with a traditional roof. Add in the savings on utilities, wear and tear on the heating and air conditioning units, and insurance, and that asphalt roof starts to look like a bad deal.
Choose steel for your next roof and enjoy the green in your wallet and the feeling of going green for the good of the environment.