Best Flat Roofing Systems In 2023

Best Flat Roofing Systems In 2023

Flat Roofing Systems: The Best Choice For Your Commercial Building

There are a variety of flat roofing system alternatives accessible to commercial building owners. The majority of commercial facilities have flat or low-slope roofs. For a number of reasons, they are not constructed with the severe slopes of a typical roof:

Initial Building Expenses

Because of the height and quantity of materials required for the roof support system, a sloping roof would be unfeasible for a big commercial structure.

The difficulty and expense increase if there are peaks, troughs, or other irregular characteristics needed.

HVAC Rooftop Equipment

Heating, ventilation, and air conditioning (HVAC) systems, as well as other mechanical equipment, are frequently installed on the roofs of commercial buildings because it is a safe and convenient site. It might be challenging, if not impossible, to install an HVAC system on a roof with a high pitch.


Rooftop solar systems may best take advantage of the sun’s path across the sky when installed on flat rooftops. Solar panels may convert a vast flat roof from wasted space to a source of renewable energy.

A “flat roof” isn’t actually totally flat, so bear that in mind. In order to facilitate drainage, it is essential that roofs have a little slope. The weight of rooftop equipment or persistent accumulation of water can cause a roof to settle or flatten over time, resulting in localized changes in the roof’s slope.

Different Flat Roofing Systems Available

Commercial building owners and managers can choose from a wide variety of roofing materials and styles for their low-slope buildings. Some of the most common commercial roofing systems available today are briefly discussed here.

BUR Systems, or Built-up Roofing,

Built-up roofing gets its name from the fact that it is literally “built” by the roofing contractor directly on the roof. Hot asphalt or coal tar is used to mop together layers of felt or similar synthetic fabric. Pea gravel or other types of stone are commonly used to cover them to prevent deterioration from the sun and other elements. High fire ratings may also be possible with properly prepared gravel surfaces.

Although BUR systems have been around for decades, they are still regularly implemented. When installing a built-up roof, the quality of the mopping material and felts, as well as the availability of skilled workers, are of paramount importance.

Bitumen Membrane Modifications

As an alternative to built-up roofing, modified bitumen membranes emerged. This is a “built-up roof in a roll” made from factory-produced asphalt and fiberglass sheets, which may be put in a single layer or in many levels.

There are two varieties of modified bitumen, each requiring a unique application process. An open torch can be used to melt the material to a suitable underlayment, or hot asphalt or cold process cement can be mopped on top. The open torch approach may be hazardous because of the potential for a roof fire to break out.

Single-ply roofing systems, like those made by mod-bit, are one type of commercial roofing system. Synthetic materials such as bitumens, polymers, fillers, plasticizers, and stabilizers are used to create single plies, which are then fabricated into flexible sheets.

Thermoset and thermoplastic membranes are two further examples of single-ply products.

Thermoset Membranes

Marketed as EPDM (ethylene propylene diene terpolymer), thermoset membranes are elastic vulcanized (rubber) materials. After EPDM sheets have been produced and “set” chemically, bonding them is challenging. EPDM membranes can’t be warmed to a malleable state, hence adhesives are used to join the sheets during installation. EPDM roofing systems can be found in white as well as the more common black.

They can be bonded to an acceptable substrate, screwed and bolted to the roof, or held down with a layer of washed river rock ballast. Re-roofing projects involving the use of 12-15 pounds of stone per square foot typically require the services of a structural engineer for final approval.

Membranes made of thermoplastics

In the 1960s, Europe saw the introduction of thermoplastic membranes (mainly PVC and TPO compositions). Because they do not harden like EPDM systems but rather soften and “flow” when heated, membrane parts can be “hot air welded” to join them at seams. They’re easy to transport and, being mostly white, they reflect a lot of light.

Depending on the building’s position and environment, a white reflective membrane roof can significantly reduce cooling costs by reflecting the sun’s heat and keeping the interior cooler.

PVC Membranes

Thermoplastic VC (polyvinyl chloride) roofing membranes have been used successfully for over 40 years in the United States. It has exceptional seaming capabilities for rooftops and can withstand the elements in nearly any environment. It is also fire-, oil-, and chemical-resistant. In addition to being extremely reflective, white PVC membranes may be welded years after installation since PVC doesn’t “cure” on the roof.

PVC also offers the benefit of being installable all year round, even when weather conditions would make the installation of other systems impossible.

TPO Membranes

The primary goals in developing TPO (thermoplastic polyolefin) membranes were to create a roofing material that has the greatest features of both EPDM (flexibility, weather endurance, cheap cost) and PVC (heat-weldability, chemical resistance, reflectivity). TPO is the most used roofing material in the United States, despite its mixed performance record.

Coatings for Industrial Roofs

To a limited extent, commercial roof coatings are a viable short-term solution for elongating the service life of low-slope roofs. Coatings are less disruptive to apply than a total tear-off and re-roof, and they save money on energy costs by reflecting the sun.

Silicone and acrylic are the most common types of roof coverings. Whether there will be an accumulation of water, how long the coating has to endure, how much it will cost, and other considerations all play a role in deciding which is the best option.


It is crucial to hire a commercial contractor that is familiar with the advantages and disadvantages of each roofing material for your business. For over 20 years, SW Commercial Roofing has served as the region’s go-to commercial roofing contractor, specializing in the installation of single-ply membranes and metal roofs for business buildings.

Let’s get started on your commercial roofing project!

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