A Property Manager’s Comprehensive Guide to Flat Roofing

Flat roofs can get a bad rap but unnecessarily so. When you choose the right product for your building and hire an experienced roofing team, you set yourself up for a great roof that will last you for 25 or even 30 years with little maintenance!

What constitutes a flat roof?

A flat roof is a roof with a pitch from 1-10 degrees. Yes, even a flat roof has a slight pitch to it that allows water to drain off its surface.

Membrane or single-ply roof

These roofs are made from a rubber or plastic compound. The EPDM membrane, composed of synthetic rubber, is the most common membrane material. 


  • An EPDM roof is highly waterproof and easy to install.
  • An EPDM roof is lightweight and doesn’t require decking reinforcement.
  • Repairs to flat roof membranes are easy to perform and are often completed without hiring a professional.


  • The membrane is prone to punctures from branches that land on the roof during storms, critters who make nests on the roof and frequent foot traffic during inspections. 
  • It’s not uncommon for single-ply membranes to allow water seepage between seams if improperly installed.

Built-up roofing (BUR)

These roofs are layered with waterproof membranes, tar and gravel. 


  • They are relatively inexpensive.
  • They are highly durable, making them an excellent choice for industrial applications.
  • They are low maintenance and affordable to maintain.
  • They are durable in harsh weather conditions and resistant to foot traffic.


  • The gravel can clog gutters.
  • The materials emit hazardous fumes during installation. 
  • The installation is messy and the multilayer design is labor-intensive to install. 
  • It’s difficult to find the source of a roof leak.
  • The roof is heavy and often requires decking or roof joist reinforcement.

Modified bitumen roofing (MBR)

Developed in the 1960s, these roofs are a lighter-weight alternative to the BUR roofing system. MBS roofing comes in rolled asphalt sheets that are adhered to a base membrane by heat or adhesive.


  • The installation doesn’t require the use of hot, toxic chemicals to adhere the layers to the roof surface.
  • They are more affordable to install than BUR roofs because they require less installation time.
  • They are durable and require little maintenance.
  • Most of the materials can be recycled, much like asphalt shingles, for a more environmentally friendly choice.
  • The materials are flexible in cold weather.


  • The most common application requires an open-flame to heat the backing and adhere it to the membrane. 
  • Leaks can occur when joints aren’t properly installed. 

General flat-roof pros

Because flat roofs are easier to navigate on foot, they are also easier to inspect. This is particularly important for commercial buildings since they require frequent maintenance and inspections. They can also be more energy efficient which, when translated across multiple units or buildings, can add up to hefty energy savings!


General flat-roof cons

Because of their lower pitch, flat roofs drain slower. That means that ice and snow sit on a flat roof longer than on a roof with a steeper pitch. The presence of standing water during spring thaws or after heavy rains can contribute to leaks. Also, because HVAC systems and chimneys exit through flat roofs, roofs can leak around penetrations if proper flashing isn’t installed or maintained. 


Let Hoyt Exteriors put your mind at ease with a flat roof best suited for your commercial building!

When you work with Hoyt Exteriors, you can rest assured that we only use the highest quality flat-roofing products including Duro-last and Mule Hide. 

Our single-ply membranes are precisely measured to fit the exact measurements of your roof, providing a long-term waterproof seal. They are durable, energy-efficient and last just as long as other types of roofing. We have extensive flat-roofing experience and can install flat roof coverings with little hassle, noise or hazardous materials. 

Give us a call at 651.212.4965 or contact us here to schedule a roofing inspection or discuss the installation of a flat roof for your commercial building!

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