How to Repair Rubber Roof Seams

  • 2-8 hours
  • Intermediate
  • 2,000-6,000
What You'll Need
Absorbent cloth
EPDM cleaner
Rubbing alcohol
Rubber gloves
Seams Probe Tool
Silicone hand roller
Solvent-based seam cleaner
EPDM seam adhesive
Seam tape

Information about techniques for the repair of a rubber roof may come in handy for you if your home or other building has a flat roof covered with (Ethylene propylene diene monomer) rubber. Typically, repair of these roofs involves re-sealing seams that have separated and are allowing moisture to enter and leak through your building's roof system. Although the installation of these rubber roofs can be technical enough to require trained and experienced roofers, you will likely be able to repair your rubber roof seam leaks if you have the right material, tools, and instructions.

Step 1 - Locate and Clean Your Separated Seam

Locating a separated seam on an EPDM rubber roof will usually require that you walk on your roof. To do this without puncturing or damaging the rubber membrane, watch for small stones or debris that could puncture it if stepped on. Examine all seams on your roof for splitting or separating. Mark those you find. Separate the leaking seam to about 12-inches or more from the leak. This will give you a clean broad surface to apply your adhesive to. Use an EPDM cleaner to remove dust, dirt, or debris on the seam surfaces that are dusty or stained. Apply more than 1 application if necessary to clean the seams. Allow these surfaces to completely dry before applying adhesive.

Step 2 - Apply EPDM Adhesive

Using a soft brush, apply your EPDM adhesive to the bottom and top surfaces of the seam. The area to be covered by the adhesive on both top and bottom surfaces should be 6 to 8-inches wide. Apply the adhesive into the corner of the surfaces where the two-seam surfaces meet.

Step 3 - Roll the Seams Together

With the adhesive applied to both surfaces of the seam, press these seams together. Work a roller along the top surface, pressing down to remove air bubbles. Avoid applying this adhesive in a strong wind that could separate the surfaces of the seam before the adhesive is dry. After 24 hours, check the seam to be sure the adhesive has cured, then use a seam probe tool and gently insert it into the outer edge of the seam. If you are able to push the tool into the seam without effort, this will indicate that the adhesive was not successful in gluing the seam layers together. Then, you'll need to apply more adhesive to the two surfaces and press them together again.

Step 4 - Apply Seam Tape

When you have checked your seam and have determined that it is firmly glued, it is now time to finish sealing by applying seam tape. In applying the tape, begin pressing it down onto the seam about 12-inches in advance of the place on the seam where you applied the new adhesive. When you reach the far end of the newly glued seam with the applied tape, continue for another 12-inches or more before cutting the tape. Press the tape down onto the seam, using the EPDM roller.