Unlike a typical roof on a home, with its highly sloped pitch and shingles, commercial roofs are more likely to be flat or low-sloped. The reason for this preference for flat roofs is due to their economic advantages.
A residential roof requires considerably more building materials, such as decking and shingles, and because of its steep slope has more square footage. While they are much larger than residential structures, commercial buildings with low slopes require relatively less materials than if they were highly pitched.
They also have a safety advantage for installation and maintenance over a steep-sloped roof. Finally, with a flat roof, essential building equipment such as heating and air conditioning can be placed on the roof, rather than the parking lot, saving valuable space for the building.
Dustin Haney of DK Haney Roofing notes, “A flat or low-sloped roof is the overwhelming choice for most architects and commercial builders and there is a wide range of choices for the composition of these roofs – from the traditional to the technologically advanced.
“A built-up roof, sometimes called a “tar-and-gravel” roof, has been employed on flat roofs for many years. With this, alternating layers of roofing felt (usually fiberglass) and hot-applied asphalt are combined to create a long-lasting roof system.
“However, traditional materials and methods for repairing roof leaks and replacing roofs have moved away from the gravel ballast built-up systems and toward more efficient, cost-effective processes that result in energy efficiency as well as a more durable, affordable commercial roof.
“More engineers, architects, property managers, and building owners are specifying cutting-edge single-ply roof systems in their design plans due to the quality of the products, shorter interruptions of their business operation, and solar reflective properties that result in cooler roofs, cooler buildings and lower energy costs.
“At DK Haney Roofing our highly-trained roofing specialists have expertise in all types of roofing systems, including Poly-vinyl chloride (PVC) membrane, Thermoplastic polyolefin (TPO) membrane, built-up, spray coating/waterproofing, architectural metal, modified bitumen, and synthetic rubber (EPDM). Plus, we are recognized as one of the top Duro-Last® roofing contractors in the nation.”
Challenges of a Flat or Low-Sloped Roof
Standing water is the bane of any commercial roof because, over time, this can cause serious damage and even a roof failure. Plus, most manufacturer’s warranties will be voided when there is evidence of standing water for longer than 72-hours.
“Improper drainage resulting in standing water on the roof is the single biggest reason a commercial building owner or manager should always insist on a professional roofing contractor to install and regularly inspect flat or low-sloped roofs.
“An experienced commercial roofing contractor will know how to properly seal areas around pipes during installation and where drains should be located to ensure proper drainage. He will also know what to look for during inspections. It’s amazing how much damage a clogged drain, caused by natural debris such as limbs and leaves or man-made trash such as plastic water bottles that might have been left behind by other technicians, can be done to a roof. We suggest that our clients have regularly scheduled inspections and as-needed inspections after heavy storms.
Commercial Membrane Roofing Materials
Technological advances have arrived in the roofing industry and they have proven to be a great enhancement for flat and low-sloped roofs. These membranes are made from thermoplastic/PVC, synthetic plastic, bitumen or modified bitumen. The two basic types of membranes are TPO (thermoplastic polyolefin) and EPDM (ethylene propylene diene terpolymer).
“These membrane products have forever changed the way commercial roofing is done,” said Haney. “They have so many advantages and very few disadvantages. First off, the membrane is slick and this enables efficient movement of water off the roof. Because of its lightweight, it puts less stress on the building structure than other types of roofing materials. Finally, the flexibility of membrane roofing materials allows commercial roofing contractors to mold the material to unique roof designs.
“There are always some disadvantages of any building product. With a membrane system on a flat roof, foot traffic can lead to punctures when loose nails or screws on top of the membrane are stepped on by workers. Hot weather can also cause the membrane to shrink, causing tear which can lead to water getting under the membrane. Adhesives and seam tape can degrade from UV sunlight, allowing water to flow under the membrane. This makes regularly scheduled inspections – at least once a year – so important for commercial roof maintenance.
“While we can install and maintain any type of roofing membrane, we always recommend the Duro-Last product to our clients. We have specialized in installing Duro-Last single-ply roofing membrane for 15 years. We are one of the best and top Duro-Last contractors in the nation, which has earned us our “Master Elite Contractor” status. Plus, we maintain the highest quality installation scores in the country.
“The Duro-Last roofing system is fire retardant, chemical and grease resistant, can stand up against high winds and punctures, and easily accommodates extreme temperature change. Duro-Last’s custom flashing resists ponding water and prevents roofing problems before they happen. Once installed, a Duro-Last roof is watertight and virtually maintenance-free.
Is your commercial roof flat or low-sloped? Call us for a free, no obligation inspection.