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Everything you need to know about Metal Roofing for Commercial Properties

If you own a commercial property that needs a new roof, you might be considering a metal roof. Read on to find out everything you need to know regarding metal roofs and commercial properties.


Most commercial metal roofs are made from steel or aluminum. Steel panels are made using galvanized or galvalume steel, then coated to the desired color. Copper and zinc roofs are also available from some contractors.


The thickness of metal roof panels typically ranges from 29-gauge (0.0135-inch) to 22-gauge (0.0299-inch). The gauge refers to the thickness of the metal, with the lower number representing a thicker material. The thickness of the metal can vary slightly when discussing different materials. For example, 26-gauge uncoated steel is about .0179 inches thick, whereas 26-gauge galvanized uncoated steel is about .0217 inches thick.


The short answer to the question “How long does a commercial metal roof last?” is “A very, very long time.” To give more detail, some commercial metal roofs have lasted over 100 years! Many modern metal roofs can be obtained with up to 50-year warranties.  

Building Types

Metal roofing can be found on a variety of different commercial buildings, including warehouses, churches, schools, office buildings, industrial buildings, manufacturing plants, shopping malls, resorts, community buildings, farms, auto shops, aircraft hangars, breweries, casinos, gyms, and others.


Open frame commercial buildings will often use vinyl-backed insulation. Some other buildings use rigid foam insulation materials.

Thermal Expansion

A well-designed roof system will account for thermal expansion, where the building will contract slightly in the winter, and at nighttime, and expand when it gets warmer. A 100-degree swing in temperatures can result in a total movement of 1 inch over a 120-foot long steel roof.

Flat Roofs

Metal is not recommended for flat roofs. Metal roofing should be used on roofs that have anywhere from a low slope to a steep slope.

Class-A Rating

The fire resistance of roofing materials is classified by International Building Codes. Metal roofing systems are rated Class A, in accordance with UL 790 testing standards. Class A is considered the highest level of fire resistance.


The industry standard test method for impact resistance is UL 2218. This rates the impact resistance of roofing materials from Class 1 to Class 4. Class 4 is the highest rating. Check with your roof supplier to find out the impact rating of their roofing materials. Whether a hailstone can damage a roof depends on its size, the slope of the roof, the thickness of the metal, and the speed of the wind.  


And that concludes our rundown of metal roofs! We believe that they are a worthy investment, given their durability, longevity, and safety rating. If you are considering a metal roof for your commercial property, contact a reputable contractor in your area.