Unlike residential roofing systems, commercial roofs are commonly flat and are by far the number one component in need of repair or replacement when conducting a commercial Property Condition Assessment.  Click here to learn more about flat roof systems. 

Commercial roof problems are inevitable. Leaves might collect and clog the drains. Strong winds might pick-up or blow-off roofing material. Cracks and holes might develop from excessive expanding and contracting.


Five most common commercial roof problems

Whether it’s due to a lack of maintenance, poor installation, improper roofing materials, ponding water, wind damage, material shrinkage, punctures in the surface or damaged flashing, commercial roofs should be inspected yearly.


Roof leaks are a problem for any type of commercial roof surface and can occur for any number of reasons. While most roof leaks are easy to spot, some can materialize in other ways such as mould spots, strong odors, stains & discoloration on walls and ceilings, and of course, water puddles on the floor.

It is possible for leaks to be limited to one specific area of the roof, but chances are there are multiple leaks throughout the building. In any case, water entering the building is a big problem and steps should be taken immediately to minimize interior damage.

roof leak


Ponding water, also known as standing water, occurs when there is poor or no drainage on the roof surface.  This formation of water typically develops when drains, gutters, downspouts, and other vulnerable roof components are not regularly cleaned or properly maintained.

Naturally, ponding water can lead to roof leaks, but it can also lead to other serious issues. The accumulation of ponding water adds a lot of extra weight to the roof surface, which can potentially compromise the structural integrity of your building. If not addressed in a timely manner, ponding water can become a very costly problem for a building owner.



Hail storms and high winds can wreak havoc on any commercial roof. In some cases, the damage caused by a storm can be easily repaired with minimal expense on behalf of the building owner. In other cases, the damage sustained during a storm can result in total loss.

Even minor storms have the potential to damage commercial roof surfaces allowing for moisture intrusion and separation of the membrane from the underlying substrate.  If addressed early, building owners can avoid a costly, more-extensive repair project later on.

storm damage


Mechanical damage is a broad term used to describe damage associated with equipment present on a roof in conjunction with human error. This type of damage is typically caused by pedestrian traffic, tools and equipment, heating and cooling units, communication equipment, or improperly discarded hardware.  Foot traffic is the most common culprit of punctures to single-ply roofing systems. When people walk on the roof, aggressive soles can tear through membranes. Walking on a ballasted roof can puncture the membrane.

mechanical damage


Most commercial roofing systems last between 15 and 20 years; however, that can vary depending on a number of different factors.  Regular maintenance and repair can help extend the service life of the roof, but eventually, all roofs need to be fully replaced.

aged membrane

How much does it cost to replace a commercial roof?

The average cost for a commercial roof is $10-12 per square foot.  It can add up very quickly.  Consider a 100’ x 50’ roof surface.  That amounts to 5000 square feet.  Total cost to replace can be as high as $50,000 to $60,000.