EPDM roofs, which are a common type of membrane used for a commercial flat roof, are durable but they aren't immune to small punctures and leaks. Fortunately, EPDM is one of the easier types of roofs to repair. Keep in mind, that although the following process is straight forward, it is usually a good idea to bring in a professional roofer so you can be assured that the roof is patched correctly.
1. Leak Location
The first step is locating the exact source of the leak. This is often the trickiest task as well, as where the leak water appears inside may not indicate the outer leak spot because the water may run through the attic for a bit before leaking into the rooms below. The most common spots for hidden leaks are along seams, in low spots, or near roof top penetrations. Punctures in other areas are typically immediately visible.
2. Surface Prep
Once the leak is found, the surface must be prepared. This means thoroughly cleaning the membrane in the area where the repair is to be made. A special cleaner designed to remove buildup dirt off of EPDM without damaging it is used, as is a soft bristled brush to remove any built up grime. Once clean, the membrane must be thoroughly wiped dry on the repair site.
3. Membrane Adjustment
If the membrane has pulled up or become wrinkled at all, it must be smoothed and stressed back into place. Sometimes a roofing adhesive is used to fix the membrane back into place by adhering it to the subroofing below. You don't want any wrinkles in the membrane, as these will eventually crack and lead to new leaks.
4. Primer Application
A primer is used to help ensure proper patch adhesion. There are special primers on the market formulated specifically for repairing a EPDM roof. To use, the primer is painted over the area to be patched in a large, even coat. Then, the primer is left to dry until it no longer feels tacky to the touch. This can take a half hour or longer, depending on the temperature when the patch is being applied.
5. Patching Method
The final step is the actual patch application. A patching tape is typically used to cover EPDM roof leaks. This adhesive tape is cut to be larger than the leak and then the backing is peeled off so the tape can be stuck in place. Smooth it out carefully, working from the center outward to avoid bubbles. Once applied, a roller tool is used to ensure full adhesion.
Contact a commercial roof repair service if you have a leak in your EPDM roof.