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A Guide to Commercial Roofing Systems

Updated: Nov 13, 2023

A commercial roofing system serves the primary purpose of protecting your property from the elements. While you may be more familiar with the roof on your personal residence, the most notable distinction between commercial roofing systems and residential roofing lies in the roof slope, which is influenced by the size of the building.

Residential properties, being smaller in size, typically feature a steep-sloped roof that is visible from the ground. These roofs often use materials like architectural tile, asphalt shingles, metal and slate to ensure durability and aesthetics. On the other hand, larger scale commercial buildings usually have flat or only slightly sloped roofs, which are not visible from the ground.

The materials used in commercial roofs span a wide range, based on factors such as the building's structure and the climate conditions. These materials are chosen to withstand various challenges, such as intense heat, extreme cold or even high foot traffic in specific areas of the roof.

While both commercial and residential roofing serve the purpose of protecting properties from the elements, they differ in design, materials used, and overall appearance due to the varying sizes and requirements of the buildings they cover.


With commercial roofing systems, addressing the slope of the roof is important. Roofs are classified as Low Slope Roofs (or Flat Roofs) and Steep Slope Roofs.

  • Steep Slope Roofs: These roofing systems are more commonly seen on single and multi-family homes than they are on commercial properties. With this roofing system, popular roof materials include metal, shingles, slate or tile.

  • Low Slope Roofs: These roofing systems are common on commercial properties. There are several options for flat roofs discussed in more detail below.


Low slope roofing comes in a variety of systems. Learn about the most common types of commercial roof systems and the NTRCA members who manufacture these systems.

Single Ply Systems

The key feature of single-ply roofing is its installation in a single layer, simplifying the process and reducing installation time. Within the single-ply roofing industry, there are two main categories: thermoplastic membranes and thermoset membranes. Each category offers its own set of benefits and properties, catering to different roofing needs and preferences.

Single-ply commercial roofing systems utilize materials like TPO, PVC and EPDM. These roofing systems are highly flexible and durable, making them a popular choice among building owners. They are known for their resistance to weathering that can present on the roof as peeling, cracking and other weathered damage.

TPO (Thermoplastic Polyolefin)

Scott Exteriors - TPO Roof System

TPO roofing is a widely used material on low-slope roofs in North Texas and throughout North America. A TPO system consists of reinforced roof sheets with heat-welded seams, offering excellent durability and weather resistance. TPO is highly reflective of the sun, which helps reduce energy consumption and cooling costs.

TPO is a single-ply membrane composed of polypropylene and ethylene-propylene rubber, polymerized together for added strength and flexibility. It comes in various colors, with light colors including white, grey and tan being the most popular choices.

When installing TPO roofing, several methods can be employed, including mechanical attachment, adhesion or ballasting, offering flexibility to suit different roofing needs and preferences. With its proven track record and versatility, TPO roofing has become a preferred option for many commercial and residential properties seeking a reliable and energy-efficient roofing solution.

NTRCA Manufacturers of TPO:

PVC (Polyvinyl Chloride)

PVC roofing is a single-ply membrane composed of high-quality synthetic materials, primarily polyvinyl chloride. The membrane is reinforced with polyester or fiberglass to enhance strength and stability. The top layer is enhanced with UV-resistant additives, ensuring protection against sun damage. The bottom layer contains plasticizers that make the material more flexible for an easier installation process.

Key advantages of PVC roofing is its impressive longevity, durability, energy efficiency and fire resistance. Additionally, PVC's weldability allows for seamless connections between sheets, ensuring a watertight seal and enhanced performance.

Moreover, PVC sheets can be customized to resemble standing seam roof systems by welding a pre-manufactured rib onto the surface, creating an attractive aesthetic without the high price tag. Another eco-friendly aspect of PVC roofing is that it is recyclable. The material can be reused in the production of new sheets, promoting sustainability in the roofing industry.

NTRCA Manufacturers of PVC:

EPDM Roofing (Ethylene Propylene Diene Monomer)

EPDM roofing, short for "ethylene propylene diene monomer," is a single-ply membrane composed of synthetic rubber, specifically ethylene propylene diene monomer. This type of roofing material is highly flexible, making it ideal for buildings with complex roof structures. This roofing membrane is made from a synthetic rubber derived from natural gas and oil, contributing to its impressive performance.

EPDM roofs are renowned for their durability and cost-effectiveness. Additionally, EPDM roofing materials are resistant to moisture, ozone and heat, making them suitable for North Texas' climate. They also have excellent thermal stability, allowing for expansion and contraction without compromising performance.

EPDM roofs are commonly used in low-slope commercial buildings in North Texas and throughout the world. With its exceptional elasticity and resilience, EPDM roofing ensures long-lasting performance, making it a top choice for commercial roofing needs.

NTRCA Manufacturers of EPDM:

Built-Up Roofing Systems

Built-up roofing, or BUR, systems, has been used for over 100 years in the roofing industry. It consists of alternating layers of bitumen (asphalt or coal tar) and reinforcing materials, such as fiberglass or organic felts. The layers are typically installed using hot asphalt or a cold adhesive, creating a robust and weather-resistant roof.

BUR systems are versatile and can be installed on a wide range of building types, including commercial and industrial structures. Built-up roofing offers reliable and durable solutions for various structures that stand the test of time. Its multi-layered composition ensures excellent resistance to weathering and contributes to the longevity of the roofing system.

NTRCA Manufacturers of BUR:

Modified Bitumen Roofing Systems

Modified bitumen roofing is a type of membrane roofing system that combines the durability of traditional built-up roofing with the flexibility of modern roofing materials. It is composed of asphalt or bitumen that is reinforced with synthetic materials, such as fiberglass or polyester. Modified bitumen has excellent flexibility and is temperature resistant, allowing it to expand and contract with temperature fluctuations, thus helping to prevent cracks and leaks.

Its versatile application methods include self-adhesive sheets, hot-mopped asphalt, torch application, or cold-applied adhesives, making it suitable for installation in both hot and cold temperatures.

These roofs are rated for wind, fire, and hail resistance, providing protection against storm-related damages. With its robust properties and ability to withstand various weather conditions, modified bitumen roofing proves to be a reliable and long-lasting choice for commercial and residential roofing needs.

NTRCA Manufacturers of Modified Bitumen:

Metal Roofing Systems

Pineapple Roofing - Metal Roof System

Metal roofing systems have gained significant popularity in recent years because of their durability, energy efficiency and aesthetic appeal. They find application on both low-slope and steep roofs, making them a versatile choice for various structures.

Metal roofs are renowned for their exceptional longevity and durability -- a well-designed metal roofing system can easily last 40 to 70 years. Metal roofs can withstand harsh weather conditions, including heavy rain, snow, high winds, and even hail, without incurring significant damage. They are resistant to fire, rot, and insect infestations, making them an ideal choice for long-term protection.

The reflectivity of the material and the ease of pairing it with proper insulation and ventilation systems have a positive effect on the energy efficiency of a building with a metal roof.

NTRCA Manufacturers of Metal:

Roof Coating Systems

Roofing coating systems add a protective layer to your roof's surface to fortify the roof against environmental stresses, such as UV radiation, temperature fluctuations, and moisture. Often used as an extra layer on top of another roof system, the most prevalent coatings are acrylic and silicone.

These systems involve applying a protective liquid layer to the existing roof surface, creating a seamless barrier against weather elements. The coatings provide exceptional waterproofing, guarding against leaks and potential damage. They also reflect sunlight, reducing heat absorption and improving energy efficiency. With quick and straightforward application, roof coatings minimize disruptions to business operations during installation. Additionally, roof coating systems offer cost-effective solutions to enhance durability, weatherproofing, and energy efficiency.

NTRCA Manufacturers of Roof Coating Systems:

Liquid Applied Roofing

Liquid applied roofing is a modern roofing solution that involves the application of a liquid coating or membrane onto your existing roof surface. This liquid material is created on-site using resin and a reinforcing polyester material. Skillfully spread over the roof's substrate, it creates a seamless and watertight barrier that safeguards your property from the elements.

Liquid applied roofing is a roofing membrane that is created on-site using resin and a reinforcing polyester material. This unique construction allows for excellent waterproofing performance, especially in hard-to-reach areas. Liquid applied roofing is highly versatile, making it suitable for various types of commercial roofs, including different substrates like concrete, metal and even existing roofing materials

One of the standout features of liquid applied roofing is its non-invasive nature during installation. There are no disruptive disturbances caused, and it doesn't emit harmful or strong odors, making it an ideal choice for businesses that need to remain operational during construction. This roofing method provides a convenient and efficient solution, ensuring superior waterproofing without causing any significant disruptions to the daily activities of the building or its occupants.

NTRCA Manufacturers of Liquid Applied Roofing:

Green Roofing Systems

Green roofing systems are innovative solutions that bring nature to the rooftops of commercial properties. Designed to combine environmental benefits with functional roofing, these systems consist of vegetation, soil and specialized layers that create a living, thriving garden atop your building. Although they may not be suitable for every location, green roofing systems offer a variety of benefits when implemented. They provide natural insulation, resulting in reduced energy costs. Additionally, they absorb sunlight and release it gradually, which combats urban heat islands, where cities become significantly warmer due to human activities and structures. Green roofs also significantly reduce stormwater runoff by absorbing rainwater, thus minimizing the strain on drainage systems. Moreover, green roofs extend the lifespan of your roofing membrane by shielding it from direct exposure to ultraviolet rays and temperature fluctuations. They improve air quality by filtering pollutants and carbon dioxide, providing a healthier environment. If you're looking to transform your commercial property into an eco-friendly haven while reaping the benefits of energy efficiency and improved aesthetics, green roofing systems offer a sustainable and visually appealing solution.

NTRCA Manufacturers of Green Roofing Systems:

Photovoltaic (PV) Solar Panel Systems

Photovoltaic (PV) solar panel systems are advanced solutions that empower commercial property owners to harness solar energy for sustainable electricity generation. These systems utilize solar panels installed on rooftops to convert sunlight into usable electricity through the photovoltaic effect.

Solar panels consist of solar cells that absorb sunlight, generating electrons that create direct current (DC) electricity. This electricity is then converted to alternating current (AC) using an inverter, suitable for powering a commercial property. PV solar panel systems yield numerous advantages, including reduced reliance on traditional energy sources, lowered energy costs, and decreased carbon emissions. The low-maintenance nature of solar panels ensures long-term savings while excess energy can be shared back to the grid for potential compensation.

Photovoltaic solar panel systems harness the power of natural sunlight, transforming it into usable energy. When integrated into roofing structures, these photovoltaics hold the promise of significant long-term cost savings, particularly in regions with abundant sunlight.

NTRCA Manufacturers of PV Solar Panel Systems:

Steep Slope Roofs

While common on residential homes, steep slope roof systems cater to properties characterized by prominent angles and can prove necessary for some commercial structures. These roofs are designed to swiftly divert water, snow, and debris, minimizing potential accumulation and associated hazards.

Comprising essential components, steep slope roofs include a durable roof covering like asphalt shingles, metal, tiles or wood shakes that act as the first line of defense against environmental elements. Underneath lies the underlayment, an added layer of protection against water infiltration. Flashing materials are strategically placed to seal joints and transitions, bolstering the roof's integrity. Adequate ventilation plays a crucial role in regulating the attic's climate, which helps prevent moisture-related problems.

NTRCA Manufacturers of Steep Slope Materials:

Insulation and Cover Boards

Insulation and cover boards are both integral components of a commercial property's roofing system, playing important roles in energy efficiency, weather resistance and structural integrity.

Insulation: Roof insulation is like a protective blanket for a building. It prevents the transfer of heat through the roof, keeping the interior warm in winter and cool in summer. Insulation materials come in various types, such as foam boards, mineral wool and fiberglass. Proper insulation not only promotes energy savings but also minimizes the risk of condensation and helps extend the lifespan of your roof by reducing temperature-related stress.

Cover Boards: Cover boards are protective layers placed on top of the insulation, serving as a resilient barrier against potential damage. They provide a stable surface for the roofing membrane to be applied while enhancing the roof's resistance to foot traffic, impacts and punctures thus extending the longevity of the roof system. Cover boards are available in materials like gypsum, high-density polyiso and fiber-reinforced cementitious boards.

Both insulation and cover boards work in tandem to bolster your commercial property's roofing system. By investing in proper insulation, you can optimize energy efficiency and create a more comfortable indoor environment. Incorporating durable cover boards safeguards the integrity of your roofing materials, helping to maintain the structural soundness of your property and prolonging the life of your roof.

NTRCA Manufacturers of Insulation and Cover Board:


There are numerous factors to consider when selecting a roofing system. NTRCA Commercial Contractor Members have the expertise to design, repair, replace and maintain all types of commercial roofing systems.

Our members cater to various industries, including commercial, industrial, offices, hospitality, distribution centers, retail centers and education, among others. As industry leaders serving North Texas, our members offer cutting-edge commercial roofing systems.

No matter the type or condition of your roof, our members and their teams of roofing professionals will assist you in determining the best solution for your specific needs. Find a commercial contractor at


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