Why are Flat Roofs Popular on Commercial Buildings?

From warehouses and corporate buildings to shopping malls, manufacturing plants, department stores and airports, flat roofs are increasingly popular on commercial buildings. Wondering why? A flat roof is the perfect combination of flexibility and function. Though the name suggests a level surface, flat roofs actually slope slightly. They are also known for their clean lines (which increase a building’s aesthetics) and a drainage system to prevent the clogging of water. There are many reasons why flat roofs are so popular on commercial buildings, but before we explain what they are, let’s highlight the materials used in their construction.

Important Materials Used for Flat Roofing

One of the reasons why commercial builders prefer flat roofs over others is because the materials used are relatively inexpensive and can be produced in bulk. To find out what they are, keep reading:


Thermoplastic Polyolefin (TPO) is a synthetic rubber that has the same basic properties of Ethylene Propylene Diene Monomer (EPDM). This makes it heat resistant due to the vinyl composite. It is also brightly coloured which reflects UV rays and helps with insulation. Though it is more expensive than an EPDM roof, commercial builders prefer this raw product for its sturdiness.


Polyvinyl Chloride (PVC) is a durable material used in the manufacture of flat roofing, piping systems, and furniture. PVC flat roofs can withstand weights of up to 350 pounds per inch (PPI). However, a standard commercial flat roof usually carries a minimum of 250 PPI. This raw material has made flat roofing a popular choice with the roofing industry.


Ethylene Propylene Diene Monomer (EPDM) is the most affordable material used in commercial roofs. These kinds of roofs are light in colour, reflects the sun, and help in insulation. But it may not be suitable for heavy materials as it can lead to penetration. Otherwise, it is one of the best roofing solutions and can last for more than 30 years with proper maintenance.


Though asphalt is used for building bridges and roads, a different kind is used for roofing. Manufacturers produce a special asphalt for flat roofing membranes. It is hardy, guarantees proper insulation, and can last for more than 50 years. For its sturdiness, premium hotels use this flat roof membrane in the construction of sky gardens, designer decks, and bars.


Metal is the first choice for commercial property owners because it is tough and can last for more than 50 years. It can also be repaired and restored easily. Even though it is costly, commercial roofers also prize this material for its flexibility.

Major Reasons Why Flat Roofs are Popular on Commercial Buildings  

Now, we will reveal the reasons why flat roofing has gained popularity in the commercial sector:

1. Cost

Affordability is one of the major reasons why contractors and property owners choose flat roofing. Its reasonable cost is because the simple design of a flat roof requires a minimal amount of raw material in its construction. In addition, this roof can be installed in a day or two, based on the area of the building, meaning the labour needed to construct a flat roof is less compared to other roofing options. The prices of raw materials used in flat roofs can vary but are reasonably cost effective.

2. Space Optimization

Commercial buildings require a lot of roof space, and that space can be used in several different ways. For instance, hotels can turn a flat roof into a sky garden with decks, bars, and swimming pools. Some commercial buildings use these roofs to accommodate a swimming pool. And manufacturing plants and warehouses keep their ventilation and HVAC systems on top of the building.

3. Durability

The materials used in flat roofing, including asphalt, EPDM, metal and thermoplastic membranes, are all durable. In fact, asphalt can last for 50 years and EPDM for 30 years, provided they are maintained properly.

4. Efficient Drainage Systems

Have you heard of rainwater harvesting? Possible with flat roofs, this process allows commercial properties to install a rainwater roll-off system that stores the water and prevents clogging of the roof. This system can also redistribute rainwater, using it as a renewable resource that can be used for other purposes, including filling fountains and watering plants.

5. Maintenance

Maintaining a flat roof is easy compared to other roof types. This is because detecting problems like water leakage and other damage is less complicated on a flat roof. Furthermore, repairing flat roofs is more convenient. If the roof needs to be replaced, it can be done as well without much effort. But be sure to seek professional guidance for proper maintenance.

6. Convertible Space

Commercial building contractors always look for flat roofs as convertible spaces. Many commercial properties use their roofs for extra parking; some manufacturing plants store products on their flat roofs, including air-conditioning units; and some commercial builders looking for an alternative source of electricity switch to rooftop solar panels.

From utilizing all the floor inches of a building to increasing the aesthetics of the structure, from reducing costs to increasing its life to decades, flat roofs are completely worth the cost of installation. But whenever you’re planning to construct a flat roof, be sure to contact a professional commercial flat roof contractor.

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