Blistering is common in commercial flat roofs, and it can occur in all types of roofing membranes. EPDM, TPO, and PVC membranes can all form blisters. Blisters form when expanding water pushes the membrane away from the substrate that it's attached to. While blisters don't cause water to leak into your roof, it's important to find out what's allowing moisture to build up under the roofing membrane and causing blisters to form. To learn more about why commercial roofing membranes form blisters and what you should do if you notice that your roof is blistering, read on.
What Causes Commercial Roofing Membranes to Blister?
Blisters in commercial roofing membranes occur when water trapped underneath the membrane begins to expand. Roofing membranes become very hot when they're exposed to sunlight, so water under the surface of the membrane can turn into steam. The rapid expansion of water creates pressure underneath the membrane, causing the surface to form blisters.
There are a few ways that water can collect underneath a commercial roofing membrane. The first is due to a leak in the membrane surface that allows water to leak through. Water can become trapped between the membrane and the waterproof layer beneath it, where it will eventually turn into steam and form blisters.
Water can also collect underneath a membrane if it's coming from within the building. This can happen in industrial settings that create a lot of water vapor as part of a manufacturing process. The water vapor rises, working its way above the ceiling of the building and collecting underneath the membrane.
Blisters can also form due to hasty installation. The adhesives used to attach the membrane to the surface of the building's roof contain water. If the water in the adhesive isn't allowed to evaporate before the membrane is laid over it, the water will be trapped under the membrane. Blisters will form in the roofing membrane shortly after installation is finished.
Does a Blistered Commercial Roof Need Repairs?
In general, blisters in a commercial roofing membrane are only a minor problem. They don't compromise the waterproof surface of the membrane, so the roof will still continue to repel water and keep your building dry. However, the materials used in commercial roofing membranes can begin to turn brittle due to ultraviolet light exposure. If you have an older membrane that has become brittle, a blister forming in the membrane can cause it to crack, and a cracked membrane will allow water to leak through it.
While the blisters themselves may not cause problems except in very old roofs, it's important to find out what's causing them. If you have a leak in your roof that's allowing water to collect under the membrane, for example, then the leak needs to be found and patched before the leak worsens and allows water into your building.
What Should You Do if You Notice Blisters Forming on Your Roof?
If you notice blisters forming on your building's roof, call a commercial roofing contractor and have it inspected. If the blisters are due to water vapor rising through the ceiling in your building, vents can be installed that divert water vapor away from your roof. If a leak is causing your roof to blister, it can be found and fixed before it causes more substantial roofing damage in the future. Finally, any sections of your membrane that have cracked due to blisters forming in it can be removed and replaced in order to prevent water from leaking through your roof.
For more information about your commercial roofing needs, contact a roofer like Tillotson Enterprise Inc.