This series of blog posts on commercial roofing system pros and cons review the most popular types of roofs for commercial buildings — TPO, EPDM, asphalt, slate and tile, vegetative, and, this month, metal commercial roofs. Metal roofs are steadily increasing in popularity and while you may not currently have a metal roof, it’s worth it to become familiar with this newer option.
You can also see our Guide To Commercial Roofing Systems: Pros and Cons that covers the highlights of each system in a PDF you can view online or download.
Metal Commercial Roofs
Metal commercial roofs are attractive, insulating and can be very durable. They’re made from a variety of metals and are covered with a coating to protect against the sun, weather and corrosion. These are the different kinds of metal used, either on their own or in combination:
● Galvanized steel (most popular)
● Silicone-coated steel
● Stainless steel
It’s important to choose the right profile metal. The existing roof slope and complexity of roof penetrations and architectural features will impact the design options.
Metal roofs generally require a minimum 1” in 12” fall to adequately perform. They can be installed over a solid substrate or open framing. Light gauge metal framing packages are available to transform an existing flat roof to a sloped substrate for a new metal roof system. The two basic types are:
· Architectural panel: A metal roof panel that requires a continuous or closely spaced substrate and relies on slope to shed water.
· Structural panel: A metal roof panel designed to be applied over open framing rather than a continuous or closely spaced roof deck
Roof insulation can be added directly below the roof panels, or in attic space to provide the required thermal resistance.
Metal Roofing – The Pros
One of the reasons more people are choosing metal commercial roofs is long-term durability. Combined with substrate insulation, this system easily complies with today’s more stringent energy code requirements. A properly designed and installed metal roof can last up to 50 years.
Other advantages of include:
● Lower lifecycle costs
● 20 – 30 year warranties
● Minimal maintenance
● Physically durable
● Vast array of systems and finishes
● Reduced carbon footprint
Another advantage: most metal roofing systems are made from recycled materials. This means fewer new materials were sourced to create metal commercial roofs. And if you decide to re-roof using a different type of roof, most of the materials from your metal roof can be recycled again and kept out of landfills.
Metal Roofing – The Cons
The most common problems with metal roofs have to do with the specific materials or design used and the quality of the installation. If a metal roof includes a fastener system that’s exposed, for example, you could start seeing some leaks in seven to ten years. Canceled fastener design prevents this but adds to the complexity of the installation. Choose a contractor with lots of experience.
It’s also more difficult to walk on a metal roof and can even be dangerous — they are slippery! If your roof has a lot of equipment on it or many protrusions like vents and skylights, it will be harder to install the system, service the equipment and perform regular maintenance around the protrusions.
Metal roofing systems can be warranted from 5 to 30 years and cover materials including panels, underlayment and even paint finish. Review these options with your roofing professional before selecting your roof to determine which will best meet your needs and fit your roofing asset budget.
Sentry Roof has a lot of experience with metal roofs and complex (and beautiful) metal roof installations. Metal roofs are often used as an architectural feature so precision installation that looks flawless is critical. If you have a metal roof that needs maintenance or repair, or you’re interested in installing one, please let us know. We’re happy to answer any questions you may have.