Your commercial roofing system represents a significant investment and is a business asset — but, like everything else, it won’t last forever. Do you know how long your type of commercial roof was designed to last? How long a roof will last is one of the most common questions we get at Sentry Roof so here’s a look at the top commercial roofing systems and their lifespans.
Typical thermoplastic olefin (TPO) roofs usually last between 10 and 20 years, although they may last longer. TPO technology continues to improve — some newer, heavier TPO systems are warrantied for up to 35 years. TPO is typically used on flat roofs, such as the kind you find on shopping centers, large warehouses and sprawling office buildings. When a TPO roof is regularly maintained and repaired by an experienced TPO roof technician, you can expect this type of commercial roof to last until the upper end of its projected lifespan.
Ethylene propylene diene monomer (EPDM) roofs have lifespans of up to 30 years when properly maintained, with a 20- to 30-year lifespan being average. EPDM roofing systems are resilient and resistant to thermal shock and hail — the durable synthetic rubber membrane is key to their longevity. Industrial-grade, synthetic rubber is slow to show signs of degradation under normal conditions. Like TPO roofs, EPDM roofs are typically flat, commercial roofs that are installed on large buildings.
PVC (polyvinyl chloride) commercial roofs last up to 35 years. They are the original heat-welded single-ply roofing systems and have been around since the 1960s. While they are susceptible to shrinkage and incompatible with asphalt, PVC systems are durable, flexible, and excellent at resisting rooftop chemicals, oils, greases, fungi, fire, and industrial byproducts.
Metal roofs can last up to 50 years (and often do) when installed on steep-slope roof structures. Lifespan is largely determined by the roof slope, the type of metal they contain, the metal’s finish and, of course, regular maintenance. Metal roofs are made from a variety of metals — including galvanized steel (the most popular), aluminum, zinc, copper, and stainless steel — either alone or in combination, and are covered with a coating to protect against the sun, weather, and corrosion.
Professionally installed low-slope asphalt roofs usually have a lifespan of between 10 and 25 years. Steep-sloped shingle asphalt roofs can last even longer. The lifespan is determined by the roofing system design, quality of the shingles, and proper maintenance. Typically used on low-slope structures, asphalt roofs consist of several layers — a weather-proofing layer, one or more reinforcement layers, and a protective surface layer.
Slate and Tile
Slate and tile commercial roofs last the longest — life expectancy is up to 150 years for natural slate and 100 years for natural tile. You can expect about half that lifespan from synthetic slate and tile products. These roofing systems have been around for more than 4,500 years and come with warranties of 50, 75, or 100 years for natural products and labor warranties for up to 20 years. Most synthetic slate roofs and concrete tile roofs have 50-year warranties.
Vegetative commercial roofs (also known as green roofs) have a living vegetative layer on top of a conventional flat or sloping roof so their longevity is tied to the roofing system that’s installed underneath the plants — life expectancy varies greatly. The plants protect the roof membrane by shielding it from the elements so you can expect the maximum lifespan from the membrane you choose. Learn more at greenroofs.org.
Extending the life of your commercial roof regardless of its type
You’ll notice that the lifespan for your type of commercial roof involves a range of several years. In addition to maintaining your roof and performing timely repairs, you can extend your roof’s lifespan so that it reaches the upper end of that range by going with better roofing materials and a better roofing system design. Just as building products aren’t created equal, neither are roofing systems. Some are cheaply designed and last just a few years, while others are exceptionally well-designed and last a lifetime.
As an example of how commercial roofs can be engineered to have different lifespans, see this helpful resource from Firestone that describes the composition of different roofs and places a warranty on the products based partly on their expected lifespan.
For more information on the commercial roofing systems discussed here, please see our Guide to Commercial Roofing Systems: Pros and Cons.
Full-service roofing contractors like maintain, repair and install every type of commercial roof — your roof is an asset that should be managed like your other business assets regardless of roof type or how old your roof is. Knowing how long it’s expected to last sets the bar for expectations but how you take care of it will determine it’s actual lifespan. An annual roof maintenance program from a reputable full-service commercial roofing contractor is the way to go if you want to get an extra 25% of life out of your roof.