types of commercial flat roofs

Introduction to Commercial Flat Roofs

As a commercial property owner or facility manager, the choice of roofing system can have a significant impact on the functionality, energy efficiency, and overall aesthetic of your building. One popular option that has gained increasing attention in recent years is the commercial flat roof. These roofs offer a range of benefits, from their sleek and modern appearance to their cost-effectiveness and ease of maintenance.

In this comprehensive guide, we will delve into the world of commercial flat roofs, exploring the various types, their advantages and disadvantages, and the key factors to consider when selecting the right solution for your property. Whether you’re constructing a new building or in need of a roof replacement, this article will provide you with the knowledge and insights to make an informed decision that aligns with your specific requirements.

Advantages and Disadvantages of Commercial Flat Roofs


  • Increased Usable Space: Flat roofs offer the opportunity to utilize the rooftop area for various purposes, such as HVAC equipment, solar panels, or even recreational spaces.
  • Cost-Effective Installation: Compared to their sloped counterparts, flat roofs generally require less material and labor, making them a more budget-friendly option.
  • Ease of Maintenance: Flat roofs are typically easier to access and inspect, allowing for more efficient and cost-effective maintenance and repair.
  • Versatility in Design: Flat roofs provide a clean, modern aesthetic that can be easily integrated into a wide range of architectural styles.


  • Potential for Pooling Water: Flat roofs require proper drainage and slope to prevent the accumulation of water, which can lead to leaks and structural damage if not addressed.
  • Shorter Lifespan: Depending on the roofing material, flat roofs may have a shorter lifespan compared to sloped roofs, necessitating more frequent replacements.
  • Limited Insulation: Flat roofs may provide less insolation than sloped roofs, potentially leading to higher energy costs for heating and cooling the building.
  • Accessibility Challenges: Accessing and maintaining a flat roof can be more challenging, as ladders or specialized equipment may be required.

Built-Up Roofs: Understanding the Basics

Built-up roofs (BURs) are one of the most traditional and widely used types of commercial flat roofs. These roofs are constructed by layering multiple piles of reinforced felt or fabric, typically coated with asphalt or tar, and then topped with a final layer of gravel or a smooth surface.

The key advantages of built-up roofs include their durability, fire resistance, and ability to withstand heavy foot traffic. They are also relatively cost-effective and can be customized to meet specific performance requirements. However, BURs can be more labor-intensive to install and may require more maintenance over time, as the layers can become brittle and prone to cracking or leaking.

Single-Ply Roofing: Exploring the Options

Single-ply roofing systems have gained popularity in the commercial roofing industry due to their ease of installation, energy efficiency, and versatility. These systems consist of a single, continuous membrane that is mechanically or adhesively attached to the roof deck.

The most common types of single-ply roofing include:

  • Thermoplastic Polyolefin (TPO): TPO roofs are known for their reflective properties, which can help reduce energy costs, and their resistance to UV radiation and chemical exposure.
  • Ethylene Propylene Diene Monomer (EPDM): EPDM roofs are made from a synthetic rubber material that is highly durable and resistant to weathering, making them a popular choice for commercial buildings.
  • Polyvinyl Chloride (PVC): PVC roofs offer excellent resistance to chemicals, fire, and punctures, as well as superior energy efficiency through their reflective properties.

Each type of single-ply roofing system has its own unique advantages and disadvantages, so it’s essential to carefully evaluate your specific needs and requirements to determine the best fit for your commercial property.

Modified Bitumen Roofs: A Reliable Choice

Modified bitumen roofs are a hybrid roofing system that combines the benefits of traditional built-up roofs with the ease of installation and maintenance of single-ply membranes. These roofs are composed of a reinforced asphalt-based membrane that is either torch-applied or self-adhered to the roof deck.

The key advantages of modified bitumen roofs include their durability, flexibility, and resistance to weathering and UV exposure. They are also relatively easy to repair and maintain, making them a popular choice for commercial buildings. However, the installation process can be more complex and may require specialized equipment and training.

EPDM Roofs: The Benefits of Rubber Roofing

Ethylene Propylene Diene Monomer (EPDM) roofs are a type of single-ply roofing system that has gained significant attention in the commercial roofing market. EPDM is a synthetic rubber material that offers a range of benefits, including excellent weathering resistance, flexibility, and ease of installation.

One of the primary advantages of EPDM roofs is their ability to withstand extreme temperatures, from scorching heat to frigid cold, without compromising their integrity. They are also highly resistant to UV radiation, ozone, and chemical exposure, making them a durable and long-lasting choice for commercial buildings.

EPDM roofs are known for their seamless installation, which can help minimize the risk of leaks and improve the overall aesthetic of the building. Additionally, EPDM’s reflective properties can contribute to energy savings by reducing the building’s cooling load.

TPO Roofs: An Eco-Friendly Option

Thermoplastic Polyolefin (TPO) roofs are a single-ply roofing system that has gained popularity in the commercial roofing industry due to their eco-friendly attributes and energy-efficient performance.

TPO roofs are made from a blend of polypropylene and ethylene-propylene rubber, which gives them a highly reflective surface. This reflectivity can help reduce the building’s cooling costs by minimizing the amount of heat absorbed by the roof. Additionally, TPO roofs are recyclable and contain no volatile organic compounds (VOCs), making them a sustainable choice for environmentally conscious property owners.

Another key advantage of TPO roofs is their resistance to UV radiation, chemicals, and physical damage. They are also relatively easy to install and maintain, making them a cost-effective option for commercial buildings.

PVC Roofs: Durability and Energy Efficiency

Polyvinyl Chloride (PVC) roofs are a type of single-ply roofing system that has gained widespread recognition for its durability, energy efficiency, and versatility. PVC is a thermoplastic material that is highly resistant to UV radiation, chemicals, and fire, making it an excellent choice for commercial buildings.

One of the primary benefits of PVC roofs is their reflective properties, which can help reduce the building’s cooling costs by reflecting a significant portion of the sun’s heat. This can lead to substantial energy savings and a lower environmental impact over the life of the building.

PVC roofs are also known for their long lifespan, with many systems lasting 20 to 30 years or more with proper maintenance. They are relatively easy to install and repair, and their seamless design can help prevent leaks and improve the overall aesthetic of the building.

Metal Roofs: Long-Lasting and Low-Maintenance

Metal roofs are a popular choice for commercial buildings due to their durability, longevity, and low-maintenance requirements. These roofs are typically made from steel, aluminum, or a combination of metals, and they can be designed in a variety of profiles, from standing seam to corrugated.

One of the key advantages of metal roofs is their exceptional resistance to weathering, fire, and physical damage. They are also highly energy-efficient, as their reflective properties can help reduce the building’s cooling costs. Additionally, metal roofs require minimal maintenance, with periodic cleaning and inspections being the primary requirements.

Another benefit of metal roofs is their versatility in design. They can be customized to match the architectural style of the building, allowing for a seamless integration with the overall aesthetic.

Green Roofs: Combining Sustainability and Aesthetics

Green roofs, also known as living roofs, are a unique type of commercial flat roof that combines sustainability and aesthetics. These roofs are designed to support a layer of vegetation, such as grasses, shrubs, or even small trees, which can provide a range of environmental and aesthetic benefits.

The primary advantages of green roofs include:

  • Improved Stormwater Management: The vegetation and soil layers on a green roof can help absorb and slow the release of rainwater, reducing the strain on local drainage systems.
  • Enhanced Energy Efficiency: The insulating properties of the soil and vegetation can help regulate the building’s temperature, leading to reduced heating and cooling costs.
  • Increased Biodiversity: Green roofs can provide valuable habitat for a variety of plant and animal species, contributing to the overall ecological health of the local environment.
  • Improved Air Quality: The vegetation on a green roof can help filter air pollutants and produce oxygen, enhancing the air quality around the building.
  • Enhanced Aesthetic Appeal: Green roofs can transform a commercial building’s rooftop into a visually appealing, park-like setting, adding to the property’s overall value and appeal.

While green roofs may require more initial investment and maintenance compared to traditional roofing systems, their long-term environmental and aesthetic benefits can make them a highly attractive option for commercial property owners.

Choosing the Right Commercial Flat Roof for Your Building

When selecting the appropriate commercial flat roof for your building, there are several key factors to consider:

  • Building Use and Occupancy: The specific needs and requirements of your building, such as the type of activities, foot traffic, and potential for equipment or storage, will influence the choice of roofing system.
  • Climate and Weather Conditions: The local climate, including temperature extremes, precipitation patterns, and exposure to UV radiation or other environmental stressors, will impact the durability and performance of the roofing system.
  • Energy Efficiency and Sustainability: If energy efficiency and environmental sustainability are priorities, you may want to explore options like reflective single-ply roofs or green roofs.
  • Budget and Lifecycle Costs: Consider not only the initial installation cost but also the long-term maintenance, repair, and replacement expenses associated with each roofing system.
  • Aesthetic and Design Considerations: The appearance of the roof can play a significant role in the overall aesthetic of the building, so it’s essential to choose a system that complements the architectural style and enhances the property’s curb appeal.

By carefully evaluating these factors, you can make an informed decision that aligns with your specific needs and goals for your commercial property.

Maintenance and Repair of Commercial Flat Roofs

Proper maintenance and timely repairs are crucial for the longevity and performance of your commercial flat roof. Regardless of the roofing system you choose, it’s essential to establish a regular inspection and maintenance routine to address any issues before they escalate into more significant problems.

Some key maintenance and repair tasks for commercial flat roofs include:

  • Clearing debris and removing standing water
  • Inspecting and repairing any cracks, blisters, or other damage to the roofing membrane
  • Ensuring that all flashing, seams, and penetrations are properly sealed and maintained
  • Addressing any issues with the roof’s drainage system, such as clogged gutters or downspouts
  • Regularly cleaning the roof surface to prevent the buildup of dirt, moss, or other contaminants

By staying proactive with your commercial flat roof maintenance, you can extend its lifespan, improve energy efficiency, and avoid costly, unexpected repairs down the line.

Hiring a Professional for Commercial Flat Roof Installation

When it comes to installing a commercial flat roof, it’s essential to work with a qualified and experienced roofing contractor. Proper installation is crucial for the long-term performance and durability of the roofing system, and attempting a DIY approach can lead to costly mistakes and potential safety hazards.

When selecting a roofing contractor, look for the following:

  • Licensing, insurance, and certifications from the manufacturer or industry associations
  • Proven track record of successful commercial flat roof installations
  • Familiarity with the specific roofing system you’ve chosen
  • Willingness to provide references and a detailed project timeline
  • Transparent communication and a commitment to meeting your project’s timeline and budget

By working with a professional roofing contractor, you can ensure that your commercial flat roof is installed correctly, meeting all local building codes and industry standards. This will help maximize the lifespan of your roofing system and provide you with peace of mind knowing that your investment is in good hands.


Commercial flat roofs offer a versatile and cost-effective solution for a wide range of commercial properties. From built-up roofs and single-ply membranes to modified bitumen and metal roofs, there is a wide range of options to choose from, each with its own unique advantages and considerations.

By understanding the key features and benefits of each type of commercial flat roof, you can make an informed decision that aligns with your building’s specific needs, budget, and sustainability goals. Remember to also prioritize proper maintenance and timely repairs, as well as working with a qualified roofing contractor, to ensure the long-term performance and reliability of your commercial flat roof.

If you’re in the market for a new commercial flat roof or need assistance with maintaining your existing one, our team of experienced roofing professionals is here to help. Contact us today to schedule a consultation and learn more about the best roofing solutions for your commercial property.

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