When commercial real estate owners need roof repair, roof restoration or a new roof, the choice of roofing types can be confusing, to say the least. We will explain the pros and cons of 7 commercial roofing types used in commercial roofing systems. Also, Here’s how you choose the correct commercial roofing contractor. If you need service in the Nashville area, we offer a free onsite inspection.
- EPDM (ethylene propylene diene monomer)
- TPO (thermoplastic polyolefin)
- PVC (polyvinyl chloride)
- SPF (spray polyurethane foam)
- Asphalt rolls
- Acrylic coatings
- Metal roofing
Ethylene Propylene Diene Monomer
(EPDM) roofing is commonly known as rubber roofing.
PROS: One of the biggest advantages of an EPDM roof is its price, as it is one of the most inexpensive roofing materials available. It is also comparatively easy to install and is very lightweight, so the roof deck doesn’t need to be reinforced. A high-quality EPDM roof can have a life expectancy of up to 20 years. EPDM roofs are relatively durable and do not scuff or scratch easily. Further, though EPDM roofing material is black and, therefore, absorbs the heat, it is not easily damaged by UV rays.
CONS: Now, for the drawbacks of EPDM roofing. If you’re looking for an aesthetically pleasing roof, this is probably not the type you want to choose. When rolled out on a roof, EPDM looks a bit like an unfurled inner tube. The black color, which is the color EPDM most typically comes in, can add a great deal of stress to your air conditioning systems because it absorbs the majority of the sun’s rays and exterior heat. EPDM is available in lighter colors to help it better reflect the heat, but opting for a lighter color will hike up your cost by about 30 percent. Another disadvantage is EPDM roofs are prone to puncturing, so a hailstorm, falling branch or even a service person with the wrong kind of shoes can tear a hole in your roof. While it’s easy to repair a puncture, water can infiltrate and cause major problems if not patched quickly.
Thermoplastic polyolefin roofs (TPO) have become a very popular option, especially among commercial building owners.
PROS: Like EPDM roofing, TPO is one of the more inexpensive types of roofing material and is actually less expensive than EPDM in most cases. Because TPO is white, it helps reflect the sun, thus reducing heat buildup inside your structure. Like EPDM, TPO is lightweight and can also be installed in different ways; it can be directly fastened to the roof deck or fully adhered with adhesives to the roof deck. It is also resistant to corrosion and breakdown, isn’t prone to algae growth or mildew, and it doesn’t need to be pressure washed. Another huge benefit is having heat-welded seams vs. the use of adhesives. When using TPO, the plastics in the membrane are literally melted together, creating a far more dependable bond between seams. With seams being mostly responsible for roof leaks, this is huge!
CONS: First, its quality varies widely from manufacturer to manufacturer, so unless it comes from a highly reputable maker you really don’t know what you’re going to get. Because the top layer of TPO roofing material is laminated, weak points are introduced that can cause shrinking, cracking, crazing and deterioration.
PVC, or polyvinyl chloride, roofing is composed of two layers of PVC roof material with polyester acting as a reinforcement between the layers. The layers also include additives that make the material UV-stable and flexible, while also preventing curing. Like EPDM and TPO, it is lightweight.
PROS: On a flat or low-slope roof, PVC roofing’s lifespan is comparatively long, and it is also known for its durability. PVC is additionally resistant to moisture, fire, wind, and chemicals, and the heat welding installation process used with PVC roofs creates a permanent bond between each roofing sheet and keeps the seams securely together.
CONS: There are a few downsides with PVC roofing. For one, it is an expensive option. PVC also tends to shrink over time, which can pull the seams, lift the corners and cause leaks. In cold weather, an older PVC roof is prone to shattering and puncturing, and PVC roofs can also be difficult to repair, as the hot air welds used on a new PVC roof don’t react well with an old roof. Overall, PVC and TPO are usually compared a lot since they have similar advantages and are both heat-welded. The main differences are that TPO is more puncture resistant, PVC is more chemical resistant, TPO is better for the environment, and PVC is better for fire resistance. Either choice is usually better than EPDM, though.
Spray Polyurethane Foam
A spray polyurethane foam (SPF) roof is made from a form of plastic that transforms from a liquid into a solid in a matter of just seconds, while also expanding about 30 times as it dries.
PROS: SPF roofing is a sustainable choice that can pay for itself in terms of energy savings. A good multi-layer SPF system (such as spray foam covered with layers of premium acrylic roof coating) has outstanding tensile strength and durability, with a reflective top coat that helps building owners save on energy costs. With proper maintenance and regular roof coatings, an SPF roof can last 40 years or more. The expansion properties of an SPF roof enable the product to effectively seal off gaps and crannies, making the entire roof watertight and airtight. Unlike the other options, SPF provides insulation to save both heat and A/C, enhances building structural support while being lightweight, self-curbs around protrusions, and can be used to correct ponding water or more effectively channel water to drains by simply spraying more spray foam in areas that need to be built up.
CONS: Because SPF roofing is the product of a chemical reaction between two liquid compounds, it must be applied in a carefully calibrated way or the spray foam that results will not last long-term. It can take a roofing contractor a long time to master the application of this specialized system, and specialized training is needed, as well. SPF roofing can also be difficult and expensive to remove – which may be necessary if not properly maintained.
Asphalt Rolled Roofing
Asphalt rolled roofing is commonly used on buildings with low-slope roofs. It is composed of the same materials that are used to make asphalt shingles.
PROS: Asphalt rolled roofing is one of the more inexpensive roofing types, and it is also a relatively easy type of roof to install.
CONS: Asphalt rolled roofing has a very short life expectancy compared to other types of roofs, typically lasting only about 10 years before it needs to be replaced. Since this type of roofing product is rolled out and then stuck together at the seams, problems commonly develop where the rolls join together, which increases the necessity for maintenance and repairs. It’s also not energy efficient.
Acrylic Roof Coatings
Roof coatings can be applied to a variety of roof types and are the preferred alternative to replacement approximately 80% of the time. A good system will require a primer, base coat, fabric (either full roof or only on seams), more base coat on top of the fabric to embed it, and then a final top coat. The end result is a seamless, fully adhered membrane that is robust enough to withstand heavy hail and could easily last as long as TPO and PVC with proper maintenance. Although it isn’t mainstream yet, these coating systems can actually be installed directly to ply-wood in new construction.
PROS: Acrylic roof coatings are UV resistant, very reflective and easy to work with. They also provide building owners with a prime balance between performance and cost. Repair couldn’t be any easier as caulk is usually all that is needed. Importantly, towards the end of life, simply putting another layer of “top coat” to the roof could add as many as two decades of new life.
CONS: When weathering is a factor, acrylic products are prone to losing mil thickness. They also need to be applied at 50 degrees or above. Additionally, performance is generally poor in ponding water situations, so flat roofs may need to have depressed areas built-up beforehand.
The other popular roofing type in commercial buildings is metal roofing. Metal roofs can be made from several materials including steel, metal tile sheets, copper, and aluminum.
PROS: If properly installed, and the fasteners are not exposed to the weather elements, it can last many years. Comes in a variety of colors and is aesthetically pleasing.
CONS: Materials such as steel are prone to rust when exposed to the sun. If installed with exposed fasteners, the rubber washer used to fasten the metal will begin to deteriorate in 7-8 years and will cause leaks. Also, metal roofs are prone to hail damage.
Choosing the proper roof for your commercial property should be done with the assistance of a reputable experienced commercial roofer. Call Tri-State Commercial Roofing for a free no-hassle onsite inspection at 615-784-4628. A qualified Tri-State Commercial Roofing representative will come and evaluate your roof’s condition. Then we can offer tailored solutions for any issues.