How to Install EPDM Roofing

how to install epdm roofing

At Summit Commercial Roofing, we love EPDM (a synthetic rubber roofing membrane) for its ability to stand up to virtually any climatic conditions and its ease of maintenance. We can show you how to install EPDM roofing in no time, but first, what does EPDM roofing installation drip edge involve?

Surface Preparation

The key to knowing how to install EPDM roofing lies in starting with a clean surface. This means removing all dirt, debris, grease, and other contaminants. The surface also needs to be completely dry. Any existing coverings, such as asphalt layers, need to be removed completely.

In the case of commercial roofs with drainage or ponding problems, it’s always best to call a professional for assistance. Installing new EPDM on faulty, incorrectly leveled or damaged roofing won’t improve matters. Experts can replace or re-level the roof surface using high-grade moisture-resistant OSB panels.

Pre-Installation Tasks

In order to keep sheets perfectly straight, and minimize the chances of bubbles or creases, the next step is to measure and mark the project area using chalk or a pencil. A roof requires enough EPDM membrane to cover it completely, along with a thick overhang for the adjacent walls and roof edge. During this stage, you’ll also want to install the drip batten and drip back trim at the roof’s edge to direct rainwater over the gutter.

EPDM Sheet Preparation

Once you’re ready to begin working with your EPDM rolls, you’ll need to prepare the sheets. EPDM’s versatile nature means that many projects can be handled with a single, seamless layer of up to 50 feet wide. If your commercial roof requires a larger size, we recommend calling our professionals for assistance, since improperly installed seams are one of the biggest causes of leaks and moisture damage.

The membrane needs to be completely unfurled and laid flat over the roof surface. Then the “rest” phase begins, which allows the rubber to expand naturally. On a warm day, resting can take approximately 30 minutes.

EPDM Sheet Application

After properly resting, the EPDM sheet is ready for installation. Generally speaking, it’s ideal to work with half a sheet at a time. This is how to install EPDM roofing correctly. Start with the edge facing the wall and work towards the roof’s edge.

If using water-based adhesive, the technique involves spreading adhesive onto the roof — using a paint roller — in sections of three or four feet across the leading edge. While the adhesive is still wet, roll the EPDM forward and then begin the next portion.

Bonded adhesive works differently. It needs to be applied to both the roof surface and the membrane itself. This product allows you to work with larger sections, which need to dry anywhere from 5–20 minutes before extending the membrane.


Immediately after rolling out the EPDM membrane, it’s essential to brush the surface with a large shop broom. This is designed to eliminate bubbles and provide a stronger bond. Follow the same motion as during installation.

Repeating the Procedure

Now that you have half of the membrane applied, it’s time to continue with the next half. Follow the previous installation instructions for EPDM roofing adhesive and brushing, leaving a narrow border at the roof’s edge for the finishing portion.

Finishing Touches

While small in size, the final edges take time to get just right. This step involves several individual processes:

  • Applying bonded adhesive to roof and wall edges
  • Sealing roof corners using pressure-sensitive flashing such as Elastoform
  • Creating watertight seals for any equipment with roof penetrations
  • Affixing the drip edge, wall trim and gutter trim using screws
  • Sealing all trim using silicone sealant
  • Removing excess membrane

When executed correctly, these finishing touches leave your roof beautiful and ready to handle any kind of rough weather for decades. For the best results on how to install EPDM roofing that is perfect in every sense, contact our professionals at Summit Commercial Roofing right away.

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Summit Commercial Roofing is proud to be an industry leader in commercial flat roofing replacement, repairs, maintenance and installations. Courtesy, integrity, and transparency are a big part of everything that we do. Are you ready to see why we’re one of the best commercial roofing companies in Southeast Michigan? Call (734) 564-0371 or fill out our online form today to request a quote on our commercial roofing services.

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