It’s no surprise that building owners and managers can become confused when faced with roofing decisions. There are, of course, major differences between commercial and residential roofing materials. While residential roofs come in a variety of designs, styles, and materials influenced by the design and location of the home, commercial roofs have fewer options that are influenced primarily by function and performance, often with not much aesthetic consideration.

However, that doesn’t mean that building owners don’t have choices. Commercial and industrial roofing materials have come a long way in the past couple of decades, evolving from simple protection from the elements to an integral, energy-saving element of the advanced building envelope.

There are several major types of commercial roofing materials. This post cover the four major ones that warrant consideration for most commercial and industrial buildings. Each material has its own advantages and disadvantages and any of them can be the right choice depending on your building, climate, and budget.

Thermoplastic Roofing

Thermoplastic Polyolefin (TPO) – commonly known as thermoplastic roofing – has become a highly popular roofing material even though it’s only been around for a relatively short period of time. Introduced in the 1990s, TPO is a blend of ethylene and propylene rubber which give the material both durability and flexibility. It’s fire-, ozone-, ultraviolet-ray- and mold-resistant which helps explain its popularity. Other advantages include cost efficiency and relatively easy installation. White TPO roofs are considered more energy-efficient because they reflect the sun’s ray to help keep buildings cooler. There are some disadvantages, however, including susceptibility to extreme heat and punctures, as well as unproven longevity (due, of course, to the fact that it hasn’t been around that long). Manufacturers, though, have claimed that with periodic maintenance, a thermoplastic roof should last 30 years.

Synthetic Rubber Membrane

Sometimes confused with thermoplastic roofing, synthetic rubber roofing is actually a different compound. Created from ethylene propylene diene monomer (EPDM), synthetic rubber roof membranes have been around since the 1970s and are similar to the material used as seals around automobile and appliance doors.  EPDM has proven itself an effective roofing material for large commercial buildings, with many EPDM roofs still going strong after 30 to 40 years of use.

Synthetic rubber membranes have become highly popular for low-slope commercial roofs because they are durable and long-lasting, with a low cost life-cycle and a fast installation process. EPDM is also fire-resistant, environmentally-friendly, and recyclable. Drawbacks include sometimes hard-to-find leaks (although leaks rarely occur) and not-uncommon incorrect installation – that’s why it’s critical to work with a trained and qualified EPDM roofing installation company.

Photovoltaic Solar Panels

While technically not a roofing material, photovoltaic solar panels are becoming an increasingly popular choice for utilizing commercial roof space. With rising energy costs, solar panels installed on your building’s roof can help your business save money on direct and indirect energy costs. Other advantages include minimal environmental impact, as well as the reliability and peace-of-mind that comes from utilizing a battery-powered storage system that will continue to provide energy even during a power outage. Further, PV roofing systems aren’t subject to electricity rate increases – they produce electricity at a fixed rate over the life of the system.

Of course, proper installation is critical – equipment must be installed according to manufacturer specifications and system parts must be properly grounded and connected according to code. A positive return-on-investment (ROI) currently cannot be achieved solely from reduced public grid use – it’s important to take advantage of any provincial and federal government subsidies and tax credits to achieve maximum ROI.

Green Roofing

As the name implies, a green roofing system is partially or completely created with some sort of vegetation and a growing medium installed over a waterproof membrane. Green roofs can be categorized as intensive, semi-intensive, or extensive, depending on the depth of planting medium and the amount of maintenance they need.  More sophisticated systems can include additional layers such as drainage and irrigation systems, as well as root barriers. Green roofs can provide a host of benefits to the building, the business, and the environment. Green roofs absorb rainwater, provide insulation, even create wildlife habitat. The vegetation also helps reduce urban air temperatures and combat the municipal “heart island effect” exacerbated by asphalt and concrete.

Initial installation cost is the main disadvantage of green roofs – it can be double that of a normal roof. Depending on the type of green roof, maintenance costs could also be higher, but some types of green roof have little or no ongoing cost. Some kinds of green roofs also tax the waterproofing system more, both because water is retained on the roof and because of the possibility of roots penetrating the waterproof membrane. The additional weight of the soil substrate and retained water can even strain the building’s structural support. Still, there is no denying the benefits associated with green roofing, economically, environmentally, and socially. Building occupants and the public generally love the idea of an environmentally-friendly, energy-efficient, and productive roof.