How to Apply ClassicBond EPDM Roofing

Single-ply EPDM sheet for flat & low-slope roofs (illustration only)

ClassicBond EPDM is a durable single-ply rubber membrane for flat and low-slope roofs on timber decks (OSB/ply) and suitable overlays. It provides a long-life, low-maintenance waterproofing with minimal seams and simple detailing using primers, tapes and pre-formed accessories.

1) Best use cases

• Extensions, garages, dormers, garden rooms and simple commercial roofs
• New decks in OSB3/plywood or refurb over suitable, sound substrates (with approved separation layer if required)
• Roofs with minimal penetrations and straightforward perimeters.

2) What you’ll need (map to your listings)

• ClassicBond EPDM sheet (single piece where possible)
• Water-based deck adhesive (field adhesion to timber)
• Contact adhesive (perimeters, upstands, details)
• EPDM primer (for tapes/flashings)
• Seam/Flashing tapes (splice tape, cover strip, pipe boots, internal/external corners)
• Termination bar & fixings (where chasing isn’t used)
• Edge/drip/reveal trims and compatible outlets
• Tools: silicone roller, soft broom, scissors/knife, tape measure, chalk line
• PPE: gloves, eye protection; follow adhesive/primer safety data

3) Substrate checks

• Deck: Clean, dry, structurally sound OSB3/ply; fixings flush; no loose boards or sharp projections.
• Falls & drainage: Provide positive falls; ensure outlets are fitted and clear.
• Dry fit: Unpack EPDM, unfold and relax for ~30 minutes to reduce memory.

4) Setting out & dry-lay

1. Position the EPDM to achieve minimal seams and tidy perimeters.
2. Allow slight overhang at edges for trimming after adhesion.
3. Fold back half the sheet neatly along a central hinge.

5) Field adhesion (illustration only)

1. Roll on water-based deck adhesive to the exposed timber field (not perimeters). Even, continuous coat—no puddles.
2. Lay the EPDM back into the wet adhesive, working from the hinge outwards. Use a soft broom then a silicone roller to remove air and ensure full contact.
3. Repeat for the second half of the roof.

6) Perimeters & upstands

• Use contact adhesive at roof edges and verticals. Apply to both surfaces, allow to become touch-dry, then bond EPDM carefully without trapping air.
• Trim excess; roll firmly. Fit edge/drip trims as specified.

7) Joints & penetrations

• Seams (if any): Clean and prime both mating surfaces with EPDM primer. Apply splice tape, roll firmly, then over-band with cover strip where specified.
• Internal/external corners: Prime and install pre-formed corners or flashing tape; consolidate with a silicone roller.
• Pipes/vents: Use pre-formed pipe boots; prime, fit, clamp and seal per data sheet.

8) Terminations

• Into chases: insert EPDM and seal; or use termination bar with suitable fixings at masonry/upstands, finished with a compatible sealant bead.
• Always maintain water-shedding detail above terminations (e.g., cover flashings).

9) Quality checks & common pitfalls

• Wrinkles/bridging: Work from the centre out; don’t stretch the membrane over corners—dress and roll.
• Poor bond at edges: Ensure contact adhesive is touch-dry before mating; roll thoroughly.
• Unprimed tape areas: Tapes only bond to primed EPDM—don’t skip primer.
• Drainage: Keep outlets clear; avoid ponding where practical.

10) Maintenance

• Inspect at least annually; clear debris and check trims, outlets and flashed details.
• Clean with mild, approved cleaners; avoid harsh solvents.

Product availability

ClassicBond EPDM sheets, water-based/contact adhesives, EPDM primer, tapes/flashings, pipe boots, termination bars, trims and outlets are available from Clever Shield. Use the site search to find the exact items and sizes for your project.