Common reasons why most commercial buildings use flat roofs

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A flat roof, as the name suggests, is a roof that is almost level or has a slight slope. Flat roofs are a popular feature among commercial buildings and properties due to various reasons. Unlike a sloped roof, a flat roof allows for additional space on the exterior and 

interior of the building. This extra space can be used for installing solar panels, HVAC systems, or for various other purposes. Additionally, flat roofs also provide a modern look to any commercial building. While flat roofs may require proper maintenance to prevent water pooling and damage to the structure, when installed and maintained properly, they can be a durable and cost-effective choice for many commercial building owners.

Disclaimer: This article is intended to provide general information about flat roofs for commercial buildings and should not be taken as professional advice. For a more specific consultation on your particular case, we recommend that you seek the assistance of experts in the field, such as those at Advance Roofing LLC. As a trusted provider of roofing solutions in Spokane, WA for many years, Advance Roofing LLC has been proudly providing customers with the highest standard of quality roofing services.

Why are flat roofs the most common choice for commercial buildings?

Why are flat roofs the most common choice for commercial buildings

Flat roofs are the preferred choice for most commercial buildings due to several benefits and advantages that they provide. 

  • First and foremost, flat roofs are cost-effective compared to sloped roofs. Since there is no need for complex framing and architectural elements, a flat roof installation costs less. This is an attractive proposition for commercial building owners who prefer to keep their investment costs low. 
  • Another advantage of flat roofs is that they provide additional space that can be utilized for various purposes. Commercial property owners can use this additional space for recreational areas, rooftop gardens, or even as storage space. A flat roof design helps to maximize the usable square footage of a commercial property and is an excellent option for buildings with limited space. 
  • Efficient drainage systems are another reason why flat roofs are a popular choice for commercial buildings. Commercial roofing contractors can install drains at specific intervals to ensure that there is no water pooling on the roof. Water pooling can be detrimental to the building’s structure and can lead to water damage, costly repairs, and even the development of mold. Efficient drainage systems allow water to flow off the roof and away from the building, eliminating these risks. 
  • Flat roofs are also an ideal choice for commercial buildings that require solar panels. The type of roofing material used in flat roofs is conducive
  • to integrating solar panels, making it easy for building owners to source alternative sources of energy and reduce their utility costs. 
  • Commercial property owners and roofing contractors can choose from various types of flat roofing materials, including PVC membranes, TPO membranes, and built-up roofs. PVC membranes are popular due to their durability, resistance to water damage, and easy installation process. TPO membranes are another option that provides energy efficiency, durability, and non-toxicity. Built-up roofs, commonly known as tar and gravel roofs, are among the most traditional materials used in commercial roofing systems. 

All in all, flat roofs are the most popular choice for commercial buildings due to their affordability, versatility, energy efficiency and ability to provide more usable space. Their ability to integrate solar panels and efficient drainage systems make them a great long term investment for commercial property owners. With the right maintenance and installation, flat roofs can provide durable protection for many years to come. 

Benefits of Flat Roofing 

Flat roofing is a popular choice for commercial buildings for various reasons. In this article, we will discuss the benefits of using flat roofing systems instead of sloped roofs. We will look at how flat roofs provide additional space that commercial property owners can utilize for various purposes, how they have efficient drainage systems, and how they are an ideal choice for buildings requiring solar panels. We will also discuss the different types of flat roofing materials available and their unique benefits. 


Versatility and Easy Maintenance of flat roofs

Flat roofs are often chosen for commercial buildings due their cost-effectiveness. In comparison with sloped roofs, flat roofs offer significant cost-saving benefits. Flat roofs offer significant cost-saving benefits when compared to traditional sloped roofs. The simplicity and affordability of flat roofing materials significantly contribute to their cost effectiveness. Unlike pitched roofs, flat roofing systems require fewer structural materials, which translates to reduced material costs, shipping costs, and fewer labor hours to install. 

Additionally, flat roofing materials are relatively cheaper than traditional sloped roofing materials. Polyvinyl chloride (PVC) and thermoplastic polyolefin (TPO) are common flat roofing materials that are affordable and readily available. Compared to traditional pitched roofing materials such as shingles, tiles, and metal, flat roofing materials require less investment, making them an attractive option for commercial property owners who are looking to save on costs. 

When considering lifetime costs, it’s important to remember that flat roofs have lower maintenance costs, making them even more cost-effective. Since flat roofs lack slope, they don’t accumulate snow or debris that wear down the roof over time, which is a significant benefit in regions with harsh weather. Proper maintenance is still crucial, but maintenance costs can be significantly lower for flat roofs.

In summary, the cost-saving benefits, simplicity, and affordability of flat roofing materials make them an ideal choice for commercial property owners on a budget. When considering initial and long-term expenses, flat roofing systems are a cost-effective option that wins over traditional pitched roofs. 

Durability and Longevity 

Flat roofs are known for their durability and ability to last longer than traditional sloped roofing systems. Flat roofing materials are designed to withstand harsh weather conditions such as extreme heat, rain, and snow, making them an ideal roofing option for commercial properties in areas prone to storms and bad weather. 

When installed correctly with good quality materials, a flat roof can last up to 25 years or more before requiring partial or complete replacement. In contrast, traditional sloped roofing systems like shingles or tiles may require maintenance and replacement over time, especially if not properly cared for. 

The durability of flat roofs is due to their unique design and construction. Flat roofing materials are made of strong, durable materials such as PVC or modified bitumen, which provide excellent resistance to water damage and heavy wind gusts. Additionally, flat roofs are designed to have proper drainage to prevent water from pooling on the roof surface, reducing the risk of water damage and leaks. 

In terms of water resistance, flat roofs perform exceptionally well. Flat roofing materials are designed to be water-resistant, preventing leaks and potential water damage to the building’s interior. This is especially important for commercial properties as water damage can lead to expensive repairs and downtime. 

Moreover, flat roofs perform well in heavy wind conditions due to their low profile and strong construction. Unlike sloped roofs, wind gusts can easily lift and damage roofing materials on pitched roofs, while flat roofs remain more secure and stable, making them a dependable option during windy conditions. 

To sum up, flat roofs provide exceptional durability, longevity, and water resistance, making them a solid choice for commercial properties in areas prone to storms and other extreme weather conditions. With proper maintenance and good quality materials, flat roofs can last for years without major issues or repairs, offering significant cost savings in the long run.

Versatility and Easy Maintenance

Versatility and Easy Maintenance

Flat roofing systems have become a popular choice for commercial building owners due to their versatility and easy maintenance. One of the key advantages of flat roofs is their ability to provide additional space for equipment installations, solar panels, and even rooftop gardens. These roofs are also ideal for buildings with limited square footage, as they allow for efficient use of the available roof space. 

Flat roofing systems are easy to maintain as inspections can be done by almost anyone without the need for special gear or worry about falling off. Unlike sloped roofs, which can be difficult to climb and inspect, flat roofs are easily accessible, and repairs can be carried out quickly. Maintenance activities such as cleaning gutters, checking sidings, and patching holes can be completed without difficulty.

The low-maintenance nature of flat roofs is another significant advantage. Without the sloped design that allows for accumulation of debris, leaves, or snow on traditional sloped roofing systems, flat roofs are less prone to water pooling, which results in the growth of moss and other foliage that are often responsible for water damage. This makes flat roofing systems more cost-effective, and building owners can save money that would have been spent on repairs and maintenance. 

  • There are different types of flat roofs commonly used on commercial buildings: Polyvinyl Chloride (PVC) Membranes; 
  • Thermoplastic Polyolefin (TPO) Membranes; 
  • Built-Up Roofs (BUR). 

PVC membranes are popular because of their strength, durability, and resistance to moisture, making them ideal for regions with heavy rainfall. TPO membranes are great for buildings located in hot and humid climates as they reflect sunlight, reducing energy costs. The Built-Up Roof (BUR) is made of alternating layers of bitumen, felts, and fabrics, which make them flexible and resistant to weather damage. 

In summary, the versatility and easy maintenance of flat roofing systems make them a popular choice for commercial building owners. These roofing systems offer a cost effective alternative to traditional sloped roofing systems and allow for efficient use of available space. The different types of flat roofing systems allow building owners to choose an option that best suits their building location and climate, ensuring that their building stays in top condition for many years to come. 

Flexibility in Design Options 

Flat roofs are a popular choice for commercial buildings because they provide flexibility in design options. One of the primary reasons for this flexibility is the availability of different types of flat roofing material such as Polyvinyl Chloride (PVC) Membranes, Thermoplastic Polyolefin (TPO) Membranes, and Built-Up Roofs (BUR). 

Each type of material has its unique properties and characteristics that make it suitable for different designs and applications. PVC membranes are durable and resistant to moisture, making them ideal for regions with heavy rainfall. TPO membranes are great for buildings located in hot and humid climates as they reflect sunlight, reducing energy costs. BURs are flexible and resistant to weather damage. 

With these materials, architects and building owners can achieve various design options that meet their specific needs. For instance, an extensive green roof can be achieved using PVC membranes that can be covered with vegetation to create a garden or park-like setting on the roof. TPO membranes can be used to create cool roofs that reflect sunlight, reduce heat gain, and improve energy efficiency. 

Design elements such as parapet walls, balustrades, skylights, and access hatches can also be incorporated into the design to enhance the functionality and aesthetics of the flat roof. Parapet walls can be used to create a barrier around the perimeter of the roof, 

while balustrades can be installed to provide safety and beauty. Skylights can be integrated to allow natural light into the building, while access hatches can be installed to provide easy access to the roof for maintenance purposes.

In conclusion, flat roofs offer a high degree of flexibility in design options, and building owners can choose from various types of materials and design elements to create the perfect roof for their commercial building. 

Additional Space Availability 

Flat roofs provide commercial buildings with additional space that can be utilized for various purposes. Unlike pitched roofs, flat roofs do not have slopes and angles that limit usable space. The absence of these features creates more horizontal space on the roof, which can be utilized for various purposes. 

Building owners can take advantage of this additional space by adding features such as guest rooms, relaxation areas, gardens, and many others. A guest room is a great addition to any building as it provides a space for visitors to stay overnight. Also, the open space on the roof can be converted into a garden or relaxation area where employees can take breaks and enjoy the outdoors. 

Another benefit of flat roofs is their suitability for solar panel installations. Solar panels are practical and aesthetically pleasing on flat roofs. With more space available, building owners can install larger solar panels to produce more energy. 

The availability of additional space on flat roofs is a significant advantage for commercial buildings. The lack of slopes and angles provides more usable space, which can be utilized for various purposes such as adding guest rooms, relaxation areas, and even solar panels. 

Ability to Integrate Solar Panels 

Flat roofs on commercial buildings have gained popularity due to the numerous benefits they offer. One such advantage is the ability to integrate solar panels into the roof. The flat surface of the roof provides an ideal foundation for solar panel installation, allowing for easy installation and optimal sunlight exposure. 

Integrating solar panels into a flat roof can lead to significant cost savings for commercial property owners. Solar energy can reduce and, in some cases, eliminate the reliance on traditional energy sources, resulting in lower electricity bills. Moreover, with advancements in technology, solar panels have become more affordable and efficient, making them a viable option for many building owners. 

In addition to cost savings, integrating solar panels into flat roofs has numerous environmental benefits. By using solar energy, buildings can reduce their carbon footprint and help combat the effects of climate change. Solar energy is also renewable and sustainable, making it an environmentally friendly alternative to traditional energy sources. 

However, it is crucial to consult with a roofing professional before installing solar panels. Proper installation and maintenance are essential for the longevity of the roof and the solar panels. A roofing professional can ensure that the roof is structurally sound and can support the added weight of the solar panels. They can also recommend the most appropriate flat roofing material and answer any questions about installation and maintenance.

Integrating solar panels into flat roofs on commercial buildings offers many benefits, including cost savings, environmental sustainability, and easy installation. Consulting with a roofing professional ensures that the installation is done correctly and that the roof and solar panels are adequately maintained. As more commercial property owners consider renewable energy solutions, integrating solar panels into flat roofs will become an increasingly popular option. 

Various types of flat roofs that are frequently utilized on commercial buildings

Various types of flat roofs that are frequently utilized on commercial buildings

Flat roofs are commonly used on commercial buildings as they offer additional space and are a cost-effective option for installation and maintenance. There are various types of flat roofs available, each with their own benefits and drawbacks. There are different types of flat roofs that are commonly used on commercial properties, each with their own advantages and disadvantages. 

Polyvinyl Chloride (PVC) Membranes 

Polyvinyl Chloride (PVC) membranes have become a popular choice for commercial roofing due to their excellent durability, longevity, and fire resistance properties. The membrane’s unique composition makes it highly resistant to moisture, wind, and chemicals, while also being tear and puncture-resistant. 

Compared to other roofing materials, PVC membranes have a longer lifespan, lasting up to 30 years with little maintenance required. They also offer excellent energy efficiency, reducing heating and cooling costs, resulting in cost savings for commercial building owners. Additionally, PVC membranes have minimal environmental impact, making them an environmentally-friendly roofing option. 

One of the key advantages of PVC roofing is its excellent resistance to fire, as it is self extinguishing, reducing the risk of fire damage. Furthermore, PVC membranes are also resistant to wind uplift and hail, making them ideal for areas prone to severe weather conditions. 

PVC membranes are also lightweight and flexible, allowing them to adapt to different shapes and sizes of commercial roofs. They offer an additional benefit of being installed in one single layer, without the need for any additional insulation or layers. This means that PVC roofing can also provide extra interior space, which is advantageous for commercial properties. 

To sum up, Polyvinyl Chloride (PVC) membranes offer an array of advantages that make them a preferred choice for commercial roofing. Their durability, longevity, fire resistance, energy efficiency, and environmental-friendly properties make them a cost-effective and reliable roofing system that will endure the test of time. 

Thermoplastic Polyolefin (TPO) Membranes 

Thermoplastic Polyolefin (TPO) membranes are one of the most popular choices for flat roofing in commercial buildings due to their numerous benefits and features. TPO membranes are known for its energy-efficient and cost-effective performance. In recent years, advancements in roofing technology have greatly improved the effectiveness of TPO membranes, making them an appealing option for commercial builders and owners who want to save on cooling costs.

  • One of the main advantages of TPO membranes is their durability. TPO roofing is highly resistant to tears, impacts, and punctures, which helps to significantly reduce the chances of water damage to the roof. This durability is what makes TPO membranes so well-suited to the demands of commercial roofing applications where toughness and resilience are essential. 
  • In addition, TPO membranes offer great flexibility, enabling them to accommodate any cracks or movements caused by the building’s settling or temperature variations. This ensures that the roofing system continues to function effectively, reducing the risk of leaks. 
  • TPO membranes are also recyclable and eco-friendly, making them an attractive choice for builders who are conscious of the environment. They can also be customized to meet the specific design requirements of the commercial building, thanks to their edge-to-edge fabrication capabilities. 
  • TPO membranes emit low levels of VOC (volatile organic compounds), which means that the air inside the building remains clean and healthy. The light-colored options of the TPO membranes come in white or light grey, which reflects the heat away from the building, making them ideal for areas with hot temperatures or high solar exposure. This helps to reduce the energy consumption of the HVAC system, leading to significant cost savings. 

In summary, TPO membranes offer a range of benefits, including energy efficiency, durability, flexibility, recyclability, eco-friendliness, and custom edge-to-edge fabrication. With their light colors, TPO membranes can also play a significant role in reducing cooling costs and maintaining a comfortable indoor environment. No wonder, TPO membranes have become one of the most popular choices for commercial flat roofing systems. 

Built-Up Roofs (BUR) 

Built-Up Roofs (BUR) are a popular roofing choice for commercial buildings, primarily due to their long-lasting durability. BUR is constructed of multiple layers of materials, typically consisting of bitumen (a viscous, black, and sticky form of petroleum), reinforced with ply sheets made of materials such as fiberglass or organic felt. These layers are bonded together using hot-mopped asphalt or coal tar pitch. Once finished, the roof is topped with a layer of stone or gravel to protect the underlying bitumen layers from UV rays and environmental damage. 

The installation process for BUR involves laying down layers of insulation board, followed by alternating layers of bitumen and ply sheets. Each layer is compressed using heavy rolling equipment to ensure that the layers properly adhere to one another, creating a seamless, waterproof surface. This installation process requires experienced roofing professionals due to the complexity of the installation and the specialized equipment required.

One of the key advantages of BUR is its durability. With proper maintenance and care, BUR roofs can last up to 40 years or more. Regular professional maintenance, such as inspections, cleaning, and repairs, can help to extend the life of the roof even further. BUR roofs also have excellent resistance to weather damage, UV rays, and fire. 

However, one major disadvantage of BUR is its weight. The multiple layers of materials and the added layer of stone or gravel can make BUR roofs quite heavy. This can increase the costs of installation as additional structural support may be needed to ensure that the roof can safely support the weight of the materials. Despite this disadvantage, BUR remains a popular and effective roofing choice for many commercial properties due to its longevity and durability. 


Flat roofs have become a popular choice for commercial property owners due to their cost-effectiveness, versatility, and increased space. When durable materials are used and proper installation and maintenance are implemented, flat roofs can be just as dependable and enduring as pitched roofs. 

When considering a flat roof for their property, owners should weigh the advantages and disadvantages of different flat roofing systems and materials available in the market. By consulting roofing professionals, owners can ensure that the installation process meets the best standards and ensures the longevity and safety of their property.By making informed decisions and consulting with professionals, property owners can enjoy the benefits of flat roofs while minimizing potential risks and costs. 

Frequently Asked Questions About Flat Roofs for Commercial Buildings

What are the most common types of roofs used on commercial buildings?

Built-up Roofs (BUR), metal roofs, and single-ply membranes are all popular roofing choices for commercial buildings. BUR is the most common choice due to its long-lasting durability. Metal roofs provide an aesthetically pleasing option, while single-ply membranes are a lightweight and cost-effective choice.

What factors should be taken into account when replacing or repairing a flat roof on an industrial building?

When replacing or repairing a flat roof on an industrial building, it is important to consider the size of the area to be covered, the number of layers in the existing roof, as well as any potential weight limitations imposed by the structure below. Additionally, it is important to ensure that all materials used meet industry standards for fire resistance and waterproofing.

How many square feet does a typical flat roof cover?

The exact coverage area will vary depending on the size and shape of the roof, but typically a flat roof can cover up to 150 square feet per 100 square feet of surface area.