How To Fix Tears In Your EPDM Roof

Posted on: 3 October 2016

If you have a flat roof that covers the top of your business and the roof is made out of a single membrane, then there is a good chance that the membrane is an EPDM variety. EPDM roofs are synthetic rubber roofs that are formed from a material called ethylene propylene diene terpolymer. The EPDM is between 45 and 60 mils thick, and this thickness helps your roof remain strong. However, the membrane can lose its elasticity over time and you will notice some shrinkage as the membrane ages. This will often create tears in the surface of the material. You can repair the tears if you do not want to invest in a brand new membrane roof right away. Keep reading to learn how to make the repairs. 

Cut the Roof And Prepare It

EPDM membranes will often start to shrink and tear around weak sections of the membrane. These weak areas are around the seams or penetrations where the membrane meets drains, chimneys, and other protrusions. Also, the termination points where the membrane is secured to aluminum metal bars or plates will be weak. If these areas are where you see rips and general shrinkage, then use a utility knife to cut the membrane along the seams or attachment points. This will allow the taut membrane to shrink away from the cut. 

Allow the EPDM membrane to shrink for several hours. If the weather calls for dry conditions for several days, then allow the roof to shrink over night. You will likely notice openings that are at least a few inches wide where you have made the cuts in the membrane. You will need to cover the openings with new EPDM material. Go to your local home store and buy the roofing material. The membrane will come in a variety of different widths. Make sure the width you choose is at least four or five inches wider than the gaps you want to repair. 

You also should purchase some EPDM seam tape. The tape will typically have a butyl adhesive as well as a built-in primer. The addition of the primer will save you from having to spend a great deal of time spreading a fluid across the surface of the membrane to prepare it for adhesion. You will need to clean the membrane around the seam areas though to make sure the adhesive will stick. Paint thinner and acetone can both be used for cleaning purposes, so wipe down the edges of the EPDM with your cleaner where you will be making the repair. 

Add The New Membrane

After you have cleaned the old membrane, cut the new membrane material so it is the right length to cover gaps. Set the new membrane pieces over the seam areas. Work your way down the length of each new piece of EPDM and pinch the center so it bunches up about one-half inch in the middle. This will help to reduce damage as the new EPDM shrinks. The slight give in the membrane will not only keep your roof from possibly leaking, but it will prevent the need for future repairs.

Gently fold up each edge of the new membrane material to reveal the old EPDM underneath. Cut off two to three feet of your seam tape and press the tape down along the right edge of the old membrane. Remove the backing material from the top of the tape and then fold the right hand edge of the new membrane material over the tape. Press down on the membrane. Continue placing the tape and pressing down the new strip of membrane. When you complete the right side of the repair, continue on to the left side. 

When you finish securing the new membrane, you will likely see a small elevated seam where the new membrane meets the old material. You can purchase a a liquid EPDM or rubber material to spread along the edges to smooth them out. Look for a liquid EPDM sealer or small crack filler. Spread the material along each seam edge and use a putty knife to smooth it out. 

For professional assistance, contact a company like Upson Company.