Commercial roofs fall into two main categories: steep-slope and low-slope. Believe it or not, there is no such thing as a completely flat roof.

Steep-slope roofs can be covered with shingles, slate, or metal. Low-slope roofs are classified as built-up, single-ply membrane, or monolithic sprayed foam.

Pros and Cons of Steep-Slope and Low-Slope Roofs
DeHority Residence Hall - Ball State University

Steep-slope Roof at DeHority Residence Hall – Ball State University

Steep-Slope: Pros

Most people are familiar with traditional steep-slope roofs because that’s what we commonly see on houses. Steep-slope roofs are relatively low maintenance. Debris rolls or slides off into the gutters, so you don’t have to worry about cleaning the roof, standing water, or relieving weight from accumulated debris. Steep-slope roofs also have a familiar, classic, and aesthetically pleasing look that compliments a variety of structures.

Steep-Slope: Cons

Steep-slopes have a few disadvantages. One important weakness is that they decrease utility space on the roof. On large commercial buildings, low-slopes allow large systems and equipment to live on top of the roof, hidden from ground view. This is a challenge or even impossible on a significantly sloped roof. Mounting heavy equipment or large objects on a steep-slope roof can create run-off blockage.

The most common problem arising from steep-slope roofs is clogged gutters that result from the run-off debris. This requires regular cleaning.


Hoosier Energy Headquarters

Low-slope Roof at Hoosier Energy Headquarters

Low-Slope: Pros

Perhaps most importantly, low-slope roofs provide buildings with essentially another floor. Hiding large mechanical equipment on a low-slope roof can free up space inside the building. Further, low-slopes allow for easy implementation of new technology, such as solar panels. They also make green roofing systems and rooftop gardens possible.

Low-slope roofs also require less material than steep-slope roofs, making them less expensive, more practical, and ideal for larger buildings.

Low-Slope: Cons

While low-slope roofs don’t present the challenge of clogged gutters, regular maintenance is required to ensure debris and water are regularly removed to prevent leaks and possible collapse.