Flat Roofing is very different from your traditional style roof. 

Flat roofs exist primarily on commercial buildings but can also be found on many residential homes. When it comes to roofing of any kind, Rooftop Designs is here to help.

The first thing to know is flat roofing is sort of a misnomer, flat roofs are not actually flat. If there was water it would pool and destroy the roof faster. So flat roofs are on a very small incline so the water can slide down; generally  ¼” per foot of roofing. That means every horizontal foot you travel you go up by ¼ of an inch vertically.

Types of Flat Roofing

There are many different types of flat roofing that can be applied. A Rooftop Designs professional can answer all of these questions and more but here is a quick overview:

BUR – Built-Up Roof

Built-up roofs are generally found in commercial buildings. The reason being is that they are very very heavy. Built-up roofs are made of layers of special roofing material, tar, and asphalt. All of the layers end up putting a lot of stress on the building below it so the building support is typically reinforced. This is the reason why people have moved away from this technology.

MBR – Modified Bitumen Roofing

Modified bitumen roofing is fairly close to BUR. It is generally used on city buildings that have a small slope to them and is much less heavy than BUR. There are significantly fewer layers. Reducing the overall weight but still protecting your home or building.

A side note: Bitumen is almost the same as Asphalt, though the process for finding or refining Bitumen is different from the production of Asphalt.

EPDM Rubber Roof (ethylene propylene diene monomer)

An EPDM rubber roof follows the same structure as MBR. Lightweight and durable these types of roofs can last for years and years. These sheets of rubber are essentially rolled out onto your roof with an underlay and then glued down. They have a more sleek look than the MBR or BUR systems.


These two types of roofing are generally lumped together because of the look that they have. If you see a white roof you can bet it’s one of these two. Much like EPDM rubber roofing PVC and TPO is a layered roofing system that is rolled out onto the roof.

We install or replace flat roofing in MD, VA, and IL

Rooftop Designs is here to help with your commercial and residential needs. Whether you need this for a backyard gazebo project or a 10-story high rise, our professional salespeople and teams of contractors are here to help. With our partnership with CertainTeed, we can help you find exactly what you need.