The majority of commercial buildings have flat roofing, mostly because this is more efficient for the support of HVAC and ventilation units which these buildings require. Many commercial buildings need to be accessed by people, and flat roofing makes this task easier. But, there are differences in flat roofing. Flat roofing needs to be designed in a way that creates a barrier between the building interior and exterior, to prevent water damage. Flat roofing is more prone to water pooling so it is important to have a system that is impenetrable. The most common flat roofing systems are:

  • Built-Up Roof (BUR)
  • Modified Bitumen
  • Polyvinyl Chloride (PVC)
  • Silicone
  • Thermoplastic Polyolefin (TPO)
  • Ethylene Propylene Diene Monomer (EPDM)

Flat Roof Material Options

  • BUR System: This is one of the most aesthetically pleasing systems and is also durable to support heavy foot traffic. There are multiple layers in this system that enhances insulation making it energy efficient. It is inexpensive when compared to other options and can be expected to last up to 20 years, with regular maintenance.
  • Modified Bitumen: This is another multi-layered system that is great for saving energy and also reflects sunlight and heat. The granule top layer is aesthetically pleasing and the base layer overlaps the roof deck, making it highly durable. With proper care, a modified bitumen roof can last between 10 and 20 years.
  • PVC Roofing: PVC is more expensive than the previous systems, but it is worth it. This single-layer system includes a PVC membrane that can resist water and sunlight. PVC sheets are rolled out across the roof which means there are seams but with proper sealing, these are very strong and can last up to 30 years.
  • Silicone: Silicone is a good choice if you do not want to worry about seams. The silicone system is sprayed onto the roof and then cured to adhere to it. The seal is impenetrable making it an energy-efficient system but this also makes it more expensive. Silicone roofing can last up to 20 years.
  • TPO Roofing: TPO combines rubber, propylene, and ethylene to create a durable, and ‘green’ roof. The TPO system is energy-efficient and aesthetically pleasing. This roofing system also lasts up to 20 years with regular maintenance.
  • EPDM Roofing: This single-ply roofing system is popular because it can be fitted without seams. It is a lightweight but durable system and is ideal for warmer climates as it does not expand or contract with temperature changes. EPDM can also last up to 50 years.

In addition to these traditional roofing options, many commercial building owners are looking for green roof options. This type of roofing features live vegetation, which is attractive and provides a relaxing space for occupants. It is environmentally friendly, reduces water leakages, is sustainable, and also provides additional insulation to make the building more energy-efficient.


When deciding which flat roof system is best for your commercial property, you need to consider the aesthetics, durability, longevity, price, ease of installation and maintenance, and the local weather and climate. You have options and we are here to help you find the best solution for your roof. So call us today for a consultation and inspection.


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