A building’s recently installed commercial metal roofing.

On the surface, a commercial metal roof is a durable, long-lasting barrier between the inside of a commercial building and an array of weather conditions. But did you know there’s so much more to metal roofing systems?

A commercial metal roof offers a longer lifespan than most alternatives, however, no two installations are the same. There are several types of metal used to make roofing materials, and each commercial application can be installed in different ways, which ultimately impacts durability and lifespan.

Table of Contents

  • Commercial Metal Roofing: Get a Better Understanding of Various Roofing Systems
  • Why Choose a Commercial Metal Roof Over Other Roofing Materials?
  • Attachment Types: Exposed Fastener vs. Concealed Fastener Systems
    • Exposed Fasteners
      • Advantages of Exposed Fastener Systems
      • Disadvantages of Exposed Fastener Systems
    • Concealed Fastener/Standing Seam Metal Roof
      • Snapped
      • Mechanically Seamed
  • Types of Metal Roofing Materials
    • Steel
    • Aluminum
    • Zinc and Copper
  • When Should I Consider Retrofitting a New Roof?
  • Upgrade Your Commercial Property’s Roof with TEMA

Why Choose a Commercial Metal Roof Over Other Roofing Materials?

While a commercial metal roof can be more expensive than other common roof options, like asphalt shingles and EPDM, it’s also the longest lasting option. Most commercial roof systems last 20 to 30 years, but a metal roof’s long lifespan can range between 40 and 70 years.

By choosing the right materials and attachment methods, you can get a roof that’s better at withstanding severe weather, debris and fire than other roofing options.

Metal roofing materials are also good for the environment. They reflect heat, reducing the energy needed for the HVAC system. A metal roof is also fully recyclable, reducing its impact on the environment.

Attachment Types: Exposed Fastener vs. Concealed Fastener Systems

There are two common approaches to attaching metal roofing panels: exposed fastener and concealed fastener systems.

Exposed Fasteners

Exposed fastener roofing is installed with screws that go through the top of the metal. There are both advantages and disadvantages to this type of commercial roofing system.

Advantages of Exposed Fastener Systems

Exposed roofing is less expensive than its standing seam counterpart, it’s readily available, and is fairly easy to install. Additionally, this type of system often utilizes wider panels, which in turn cover the roof faster upon installation. For example, a 29-gauge corrugated metal roof spans up to 2 feet 6 inches across wood purlins. This spacing makes it easy to screw into post frame buildings, giving it the nickname “barn metal.”

Disadvantages of Exposed Fastener Systems

For businesses considering metal roofing, it’s important to note that exposed fastener metal roofing systems typically have a shorter lifespan than concealed fastener roofs. This is because there are more roof penetrations and are more prone to degradation.

Concealed Fastener/Standing Seam Metal Roof

Concealed fastener/standing seam roofing utilizes interlocking seams and hidden fasteners underneath the edges of the metal sheets. Nail strip panels have pre-punched slots that use screws to hold the metal to the frame without piercing the panel. Snap lock panels have clips on the edges of panels that interlock, holding them together. Hidden fastener panels can’t be installed over open purlins, and they require a roof with a pitch of 3:12 or more for drainage.

With standing seam metal roofing, there are two common engagement methods used: snapped and mechanically seamed.


With snapped installation, the male and female panels do just as the name suggests – they snap into place. Pressure is applied to the top panel until the pieces are engaged.

Mechanically Seamed

This type of roof uses standing seam panels that are mechanically folded or crimped together after they’re attached to the building. The finished seam is waterproof, making this installation method a great choice for a variety of commercial projects.

Types of Metal Roofing Materials

Metal roofing is an energy-efficient, low maintenance commercial roofing option that has a high level of fire resistance. There are several materials, colors and coatings you can pick for your metal roof. In the end, choosing the right material for your project is a matter of balancing cost, maintenance, appearance and durability.


Steel is the cheapest, strongest and most popular material for metal roofing. It also offers the lowest maintenance costs. However, it’s also prone to corrosion, giving it an expected life span of 40 to 60 years.

Coatings increase the life of steel roofing by adding a protective barrier. The most popular coating, Galvalume, uses a mixture of aluminum, zinc and silicone. On average, this coating offers four times the corrosion resistance of galvanized steel.

Stainless steel is the longest lasting steel roofing material, but it’s also the most expensive. While it’s highly corrosion resistant, standing water can cause galvanic corrosion


Aluminum is lighter than steel, so it needs less support from the building. It’s also more malleable, so while it can withstand impacts, it’s easy to dent. Aluminum is extremely corrosion resistant, making it a great choice for areas with high humidity and heavy precipitation. This material is commonly used on roofs with a pitch of 3:12 or more.

Zinc and Copper

Both zinc and copper are long-lasting, and they develop a patina over time. These materials are expensive, which makes them less popular, and shipping can get pricey, too. These metals are usually reserved for decorative elements on buildings.

Unfortunately with any metal roof, if there is a hail storm, it’s considerably louder and can be easily dented. However, if you use a reputable, professional roofing company for installation and roof repair, the materials will likely be covered under a warranty.

When Should I Consider Retrofitting a New Roof?

A retrofit roof is built on top of an existing roof, and can be an extremely cost-effective option for business owners considering commercial metal roofing.

Sub-purlins are installed over the old roof, providing points to attach new roofing sheets. If you’re having drainage issues with your pre-existing flat roof, a new structural system can be installed below the metal panels using supports of varying heights  (which create a slope that allows precipitation to run off the roof).

Metal roof installation continues to grow in popularity because it saves time and money in the long run (especially with a retrofit situation). Thanks to metal’s longevity, businesses are able to save on the cost of multiple roof replacements over the course of several decades. But, keep in mind that before you go this route, you need to make sure your building’s structure can handle the additional weight. That’s why working with a professional commercial roofing company is essential.

Upgrade Your Commercial Property’s Roof with TEMA

When it comes to nailing down a metal roofing contractor, TEMA Roofing Services can help with all of your questions and commercial roofing projects.

Our roofing solutions are unmatched, and our goal is to create a lifelong partnership with your organization. Contact us today to start talking about installing a commercial metal roof or any other commercial roofing services your business might need.