The Roofing Resource Blog

Addressing Wind Damage For Flat Commercial Roofs

Fri, Apr 24, 2015 @ 08:00 AM | Exterior Pro Roofing

It's just a little wind. Most commercial business owners will hear the wind pick up outside and never give it a second thought unless the lights begin to flicker and the electricity goes out to affect operations. Yet you should also be aware that any time the wind picks up outside, your commercial roof is taking the brunt force of it. Yes, that structure above your head can be seriously affected when the wind picks up outside as damage from a little wind can cause the roof system to fail.


Many commercial buildings have flat roofs to accommodate mounted HVAC systems. While we call the roof flat, there is still a slight pitch to direct water off of the roof so that it is does not pond on the surface and rot out the roof. Yet when you add the extra element of wind, the roof can sustain enough damage to allow moisture to get underneath the felt sheets, bitumen or EPDM roofing materials. Understanding how wind can damage commercial roof systems allow you to take the necessary steps to get early repairs to prevent further damage.

Understanding Flat Roof Systems

Flat commercial roof systems can have one of 5 different roofing materials: Ethylene propylene diene monomer (EPDM), modified bitumen, built-up roof, single ply and metal. Each roofing material that is placed on a flat roof ends along the edge where the roof meets the wall. Metal flashing and fascia will be put in place to protect the materials from wind and rain.


Wind Uplift

A major problem that commonly affects flat roof systems is wind uplift -- where the strong air gets underneath the roof materials and pulls them up. This problem leaves the roof looking like it has wrinkles or bubbles underneath the surface because the roofing membrane or materials are no longer securely attached.

When roofing membrane is pulled up from the surface, rain can get underneath and begin to rot out the materials. To prevent such wind uplifting, the metal edge flashing should be fastened securely. It is also important to fasten down fascia as it can tear off the flashing if it is loose or if a strong enough wind pulls it off. Always inspect the edge flashing and fascia for any signs of damage and have it replaced immediately.

Wind Scouring

Besides wind uplifting, another problem that may affect your flat roof system is wind scouring. Wind scouring involves when a strong enough gust pulls off the granules from the roof member, or removes the gravel placed as a surface component on built-up roofs. While there may be no immediate indication of damage, wind scouring can seriously impact the life of your commercial roof. The entire roofing system begins to deteriorate at a faster pace. In the end, you can have partial or total roof system failure that will result in the building needing a new replacement roof.

Take Wind Damage Seriously

It doesn't take much wind to cause significant damage to flat commercial roof systems. In fact, a 40 mph to 50 mph wind can pull off loose fascia and edge flashing. The stronger the wind and older the roof, the more likelihood that some damage may occur. Periodic inspections throughout the year and right after strong wind storms is recommended so that you can spot issues with your roof system.

Next time that you hear the wind banging against the office window, don't just shrug your shoulders about it. Wind can be as damaging as hail, rain, ice and snow on your flat commercial roof. Check the roof system to ensure no damage has occurred.