EPDM rubber roofing
In short
EPDM is a synthetic rubber membrane laid as a single sheet with no joints across the main area of the roof, which removes the seams that make felt roofs fail. On a domestic extension or garage it is normally the most reliable flat roof for the money.
Also called: Rubber roof · EPDM roofing · Firestone rubber roof · Single sheet rubber roof
Signs you need this
- A felt flat roof at the end of its life needing replacement
- A new extension, garage or dormer needing a flat covering
- Repeated seam failures on an existing flat roof
- A flat roof that ponds and collects silt
- Blistering, cracking or splitting in an old felt covering
EPDM is the material that changed domestic flat roofing. It comes in wide sheets, so a typical extension or garage roof is covered in one piece with no joints at all in the field of the roof — and since joints are where flat roofs leak, removing them removes most of the failure modes at a stroke.
It is genuinely durable. The material does not embrittle in UV the way bitumen felt does, it stays flexible in cold weather rather than cracking, and it tolerates the thermal movement of a timber deck without splitting. Manufacturer warranties of twenty years are standard and the realistic service life is considerably longer than that.
Installation is the whole thing, though. The membrane is fully bonded or mechanically fixed to the deck, and everything hangs on the preparation and the detailing: a clean, dry, sound deck, correct adhesive coverage, and properly formed corners, upstands and trims. The main sheet almost never fails — what fails, when EPDM fails, is a corner formed badly or an outlet detailed carelessly.
Falls matter as much on rubber as on anything else. A flat roof is not flat: it should be laid to achieve a finished fall of at least 1:80, and because timber decks and workmanship are never perfect the industry designs to 1:40 to actually get there. EPDM will hold standing water without leaking, which is a genuine advantage, but a ponding roof still collects silt, grows algae, loads the structure and hides problems. A quote that does not address falls on a roof that currently ponds is quoting to re-cover the problem.
The practical advantages on a domestic job are worth listing. It is quick, which matters when a roof is open. There is no hot work — no torch, no flame — which removes a real fire risk on a timber-decked roof attached to a house. It can be walked on for maintenance. And it takes complicated shapes reasonably well, though very intricate detailing is where GRP starts to look better.
The limitation is aesthetics and abrasion. It is black, it looks like what it is, and it is not the right answer for a roof that is on show from a window above unless it is finished with a surface layer. It also does not love sustained foot traffic or anything sharp, so a roof used as a terrace wants a walkway or a paved system over it rather than bare membrane.
What the job covers
- Existing covering stripped and the deck inspected
- Rotten or delaminated deck boards replaced
- Falls checked and corrected with firrings or tapered insulation
- Single-piece EPDM membrane bonded or mechanically fixed
- Properly formed corners, upstands, trims and outlets
- Insulation upgraded where the Building Regulations require it
What it costs
We don't publish a price for this yet, because a number pulled out of the air is worse than no number at all — your roofer has to honour it. On roofing it would also be close to meaningless: access is often the biggest single factor, and it varies enormously house to house. You'll get a firm price for your actual job when they ring you back, before any work starts. The quote itself is free and there's no obligation either way.
Common questions
How long does an EPDM roof last?
Manufacturer warranties are typically twenty years and the realistic service life is longer — the material itself is very stable. As with any flat roof, what actually determines the lifespan is the quality of the deck preparation and the detailing at the edges and outlets, not the membrane.
Is rubber better than fibreglass?
They are both good and they suit different roofs. EPDM has no joints in the field, goes down fast, involves no flame, and copes well with movement. GRP cures into one seamless laminate, takes complicated shapes and upstands beautifully, and can be finished in different colours. For a plain rectangular extension roof, EPDM is usually the simpler and cheaper answer.
Can I walk on it?
For maintenance, yes. For regular use as a terrace or balcony, it needs a walkway system or a paved overlay — bare membrane does not enjoy sustained foot traffic or anything sharp. That is a design decision to make before it is laid rather than after.
Does the old roof have to come off?
Almost always, yes. Laying a new membrane over failed felt means bonding it to a substrate that is already wet and already moving, and it traps the moisture that is in there. Stripping back to the deck is also the only way to see whether the deck itself has rotted, which on a failed felt roof it frequently has.
Need this doing in Macclesfield?
Tell us the job and it goes straight to our local roofer — one call back, usually the same day. Free quote, no obligation.