How to Install EPDM Rubber Roofing

If your flat roof keeps leaking or holding water, you’re not alone. Many homeowners face the same problem and end up spending more on repairs. EPDM rubber roofing is a solid fix. It’s waterproof, flexible, and can last over 30 years when installed right.

In this guide, we’ll show you how to install it step by step, what tools you need, how to apply it, and how to get a clean, lasting result. Whether you’re doing it yourself or hiring someone, this will help you understand the full process.

Tools and Materials You’ll Need

Materials:

• EPDM rubber membrane
• Water-based adhesive
• Contact adhesive (for edges and vertical surfaces)
• Seam tape and seam primer
• Edge trims and fixings
• Flashing tape (for roof edges or details)
• Rubber sealant

Tools:

• Tape measure and chalk line
• Scissors or a utility knife
• Paint brushes and rollers
• Broom and a clean cloth
• Caulking gun
• Pressure roller

Step-by-Step Guide to Installing EPDM Rubber Roofing

If you’re planning How to Install EPDM Rubber Roofing on your low-slope or flat roof, this step-by-step guide will help you do it the right way without any confusion.

1. Clean and Prepare the Roof Surface

Start by clearing off all dust, leaves, old roofing, or loose bits. The surface should be clean and completely dry. If the roof deck is uneven, you might need to install a layer of OSB or insulation boards to make it flat and ready for the membrane.

2. Position the EPDM Membrane

Roll out the EPDM sheet over the roof and let it sit for 30 to 60 minutes. This helps it settle and smooth out any folds. Make sure it covers the whole area with a little extra hanging over the sides for trimming later.

Fold back half of the sheet, keeping the other half in position.

3. Apply Adhesive

Use water-based adhesive for flat areas and contact adhesive for the edges and vertical surfaces.

Apply the adhesive to both the roof and the underside of the membrane using a roller or brush. Let it sit until it becomes tacky. This usually takes a few minutes. Then, slowly roll the membrane back over the glued section. Repeat the process for the other half.

4. Press the Membrane Down Smoothly

Use a broom or heavy roller to press the membrane onto the roof. Start in the middle and work your way out to the edges to push out any trapped air. This helps the membrane adhere more effectively, forming a strong bond.

5. Join the Seams (If Needed)

If you need more than one sheet of EPDM, make sure to seal the seams properly. Overlap the sheets by at least 75mm (3 inches). Clean the overlapping area with seam primer, then apply seam tape and press it down using a pressure roller. This creates a watertight connection between sheets.

6. Fix the Edges

Trim any excess rubber from the edges using a sharp knife or scissors. Fit edge trims to keep the membrane securely in place. You can use pre-formed corners and flashings for neat finishes around tricky areas like corners and upstands. A bead of rubber sealant helps add protection around these parts.

7. Seal Around Pipes, Skylights, and Other Openings

Cut the membrane carefully around vents, chimneys, or drains. Apply flashing tape or rubber sealant around these areas to stop water from getting through. This step is important for preventing leaks in the future.

8. Final Checks

Look over the entire roof once you’ve finished. Press down on any loose or bubbly parts. Allow the adhesive to cure for the time specified by the manufacturer before stepping on the roof or adding weight.

How Much Does EPDM Rubber Roofing Cost?

If you’re considering EPDM roofing, the cost is likely one of your primary concerns. The final price depends on several factors, including the size of your roof, the membrane thickness, and local labour rates.

Here’s a simple breakdown:

• EPDM Material Cost: £50–£80 per m²
  Thicker or branded options are on the higher end.
  
• Labour Cost: £25–£45 per m²
  This depends on your location and the complexity of the roof.
  
• Total Installed Cost: Around £80 per m² on average
  

Example: Single Garage Roof

For a small flat roof, such as a single garage, you can expect to pay between £1,000 and £1,500 in total. This includes both the EPDM and installation work. While EPDM isn’t the most cost-effective option upfront, it can last up to 50 years and requires minimal maintenance, making it a smart long-term investment for flat roofs.

Case Study: EPDM Rubber Roof Installation on a 50m² Flat Roof in Guildford

Problem:
A homeowner in Guildford had been dealing with ongoing leaks from their old felt roof. Water was seeping into the house during heavy rain, causing damp patches on the ceiling and damaging the interior. The felt covering had worn out over time and was no longer providing the necessary protection to the home.

Solution:
The homeowner decided it was time for a proper upgrade, so he contacted our team of roofers in Guildford. After inspecting the roof, we recommended replacing the old felt with a 1.5 mm-thick EPDM rubber membrane, known for its strength and long-lasting performance. Our team carefully removed the damaged felt, cleaned and prepared the roof surface, and installed the new EPDM sheet using water-based adhesive, seam tape, and edge trims. The job was completed within two days.

Outcome:
The EPDM rubber roof was fitted securely, providing the home with a new layer of protection. With the new system in place, the homeowner no longer has to worry about leaks. The roof is now low-maintenance, weather-resistant, and built to last for decades. The total cost was around £3,500, and the customer was pleased to have peace of mind with a solid, long-term roofing solution.

Conclusion

Installing EPDM rubber roofing is a smart solution for flat or low-slope roofs. It’s affordable, strong, and offers great resistance to water, heat, and UV rays. By following a clear installation process and using the correct tools and materials, you can make sure the roof holds up for many years.

If you’re not confident in doing it yourself, it’s always better to hire a professional roofer with experience in EPDM systems. However, if you’re up for it, this guide can help you complete the job from start to finish.

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