How do EPDM Roofing Installers Prepare and Install Rubber Roofs?

EPDM (ethylene propylene diene monomer) roofing is a popular choice for flat and low-slope roofs due to its durability, flexibility, and resistance to weathering. Professional EPDM roofing installers meticulously prepare the roof surface by cleaning, inspecting for damage, and ensuring dryness. They measure and cut the membrane accurately, install drip battens and trims to manage water runoff and seal seams and details effectively. Finally, sealing the seams, finishing the edges, and performing a thorough inspection will ensure a durable, watertight roof.

Here’s How Most Professionals Install EPDM Rubber Roofs

A comprehensive guide on how professional installers prepare and install EPDM roofing systems.

Step 1: Roof Surface Preparation

Preparing the roof surface is crucial for proper EPDM membrane adhesion. Here’s how it is done: 

• Cleaning: The team will remove all debris, dirt, dust, grease, and old roofing materials from the roof deck using a broom or leaf blower. A clean surface ensures proper adhesion of the EPDM membrane.

• Inspection: They will check the roof deck for damage, such as cracks, holes, or rot. If any of these are found, they will replace or repair them to ensure that the base of the new roofing system is solid.

• Drying: Installers make sure the roof surface is completely dry to avoid adhesion issues and problems like mold or membrane failure.

• Surface Suitability: EPDM membranes bond best to timber decking materials such as roofing-grade plywood or OSB sterling boards. Avoid installing over-bitumen or asphalt surfaces, which can damage the EPDM material.

Step 2: Measuring and Cutting the EPDM Membrane

The EPDM membrane measurements are critical and should be highly accurate.

• Measuring: The roofing installation team will measure the size of the roof, noting any intrusions such as a vent, chimney, or skylight. They will add extra inches around the edges to ensure complete coverage.

• Cutting: They will cut the EPDM membrane with a sharp utility knife. The cuts should be clean and exact so that proper alignment will be obtained when the element is placed in its position.

Step 3: Installing Drip Batten and Drip Trim

Installation of Drip Batten

• Purpose: Extend the roof deck to guide the water runoff to the gutter without dripping behind.

• Installation: Mount a timber batten along the roof edge wherever a gutter exists. This extension guides water perfectly into the gutter system.

Installation of Drip Trim

• Components: Drip Trim includes front and back pieces to handle water flow off the roof edge.

• Alignment: Place the backplate so that its curved top edge aligns with the installed timber batten.

• Securing: Press the backplate flush into place using the supplied nails to ensure it is properly aligned with the batten.

Step 4: EPDM Membrane Installation

Once the priming is placed on the roof, you will apply the following steps:

• Positioning: Carefully roll the membrane over the roof surface, starting from one edge and working across. Align it properly to ensure full coverage, including the overhangs. Allow the membrane to rest for about 30 minutes to relax and adapt to the roof contours, reducing wrinkles during installation.

• Apply adhesive: Fold the back half of the membrane to expose the roof surface. Apply a water-based adhesive even to the exposed area, with a 150mm perimeter (about 6 inches) around the edges of the contact adhesive. Roll the membrane back into place on the wet adhesive while smoothing out any wrinkles or air pockets left by the broom or roller.

Step 5: Seaming and Detailing

The sealing of the seams and the detailing around the roof penetrations must be ensured to avoid leakages:

• Seam Taping: At the overlapping sheets of EPDM membranes, clean the area with a suitable cleaner, followed by seam primer. After the primer dries, the tape along the seam is applied and pressed with a roller firm to get a watertight seal.

• Flashing: For roof penetrations such as vents or pipes, use pre-fabricated EPDM flashing or make custom pieces from the membrane. Apply primer to both the penetration and the membrane, then attach the flashing with the correct adhesive, ensuring it is tight around the penetration.

Step 6: Edge Finishing

Proper finishing of the roof edges ensures durability and aesthetics:

• Remove Excess Membrane: Apply a utility knife to all the excess membranes along the perimeter of the roof to provide neat edges

• Application of Edge Trims: Attach the drip edge flashing along the eaves and rakes on either side, away from the roof structure. Install it with the correct fasteners fully covering the membrane edges.

Step 7: Final Inspection and Clean-Up

Inspect the roof to ensure it is installed correctly.

• Inspection: The entire roof surface is inspected for defects. Seams and edges are checked for proper sealing. There are no air bubbles or wrinkles.

• Clean-up: All the leftover materials, tools, and debris from the roof area are removed. The waste is disposed of according to local regulations, leaving the worksite clean and safe.

Conclusion

In conclusion, a successful EPDM roofing installation hinges on professional installers' meticulous preparation and attention to detail. Key steps include thorough roof surface cleaning, accurate membrane measurement and cutting, proper drip batten and trim installation, precise adhesive application, effective seam sealing, and meticulous edge finishing. Finally, conducting a comprehensive inspection and clean-up ensures the durability and integrity of the roofing system, safeguarding against leaks and enhancing the roof's overall appearance.