Many commercial buildings have flat roofs covered by a protective membrane, either made of a polymer or an asphalt and bitumen compound. Although these roofs are durable and designed to last for decades when properly maintained, they can suffer damage. In some cases, the damage may not even be immediately obvious without the help of a professional. The following are some types of hidden damages you need to be aware of.
Leaks sometimes form around appliances or even internal drains on the roof. To the untrained eye, the roof may look whole and undamaged, but water still seeps in around the small hidden breaches. Your first sign of a problem usually occurs inside your building. You may notice water spots forming on ceilings, discover wet insulation in the attic areas, or catch a whiff of mildew and mold on the upper floor of your building.
Weak Membrane Seams
Membrane-style flat roofs have seams where lengths of membrane meet. These seams are sealed securely against leaks, but occasionally, they can weaken and peel up or separate. When this occurs, water leaks beneath the membrane and eventually through the roof. The damage isn't always immediately obvious because the seams may continue to lay flat and simply just shrink apart.
It only takes a few pinprick holes in a roofing membrane to cause water damage inside your building. These holes may not even be readily visible to the naked eye. The most likely causes of pinprick damage are acidic bird droppings, walking on the roof, and degradation from pollutants and acid rain. Installing anti-bird devices to keep birds from roosting on your roof helps prevent bird damage. As for pollutants and weathering, plan to have the roof sealed every few years to help protect against these types of damages.
Blisters form when the membrane separates from the roof decking below. Air becomes trapped inside the blister, but the damage may not be immediately visible to the untrained eye. A blistered membrane is more likely to suffer damage and develop a leak, so regular inspections should be performed so blisters are caught early.
You may only notice standing water on the roof if you go up on it after rain. Yet, there are other signs that can give away the problem, such as water and debris stains on the roof, or clogged drains and gutters. Frequent standing water can lead to roof collapse or leaks, so the cause needs to be found and fixed right away.
Contact a commercial roofing repair service if you suspect a problem with your flat roof.