Flat roofs and EPDM in Portishead
Extensions, dormers, garages, balconies and flat-roofed blocks. Repaired or replaced with single-ply EPDM, laid with proper falls, upstands and outlets.
Flat roofs across the town
Flat roofs turn up everywhere in Portishead. The character statement notes that the Marina’s waterfront buildings have flat roofs, and that East Wood and West Hill include newer flat-roofed buildings among the older pitched ones. Across the post-war estates there are flat-roofed garages, porches and rear extensions, and a lot of dormers built when lofts were converted.
A flat roof is never truly flat. It needs a fall so water reaches an outlet or gutter, and almost every leak we see starts at an edge: where the covering turns up a wall, goes round a rooflight, or drops into an outlet. Getting those details right matters more than the brand of membrane.
Flat roof work
EPDM single-ply
A synthetic rubber membrane laid in one sheet where possible, so there are few or no joints in the field of the roof. Well suited to extensions, garages and dormers.
Repairs to existing roofs
Splits, blisters and failed laps repaired where the rest of the roof is sound. If the deck underneath is soft or the roof holds water, we will say a repair will not last.
New decks and falls
Rotten decking replaced and firring pieces added to put a proper fall on roofs that pond.
Upstands and flashings
Membrane turned up the wall and protected with a lead or trim flashing, rather than relying on sealant.
Outlets and gutters
Outlets sized and positioned so water leaves the roof, and gutters and downpipes checked so it keeps going.
Insulated flat roofs
Warm-roof build-ups for extensions where the ceiling below is a living space, keeping condensation out of the timbers.
Worth knowing
Ponding is a symptom
Water sitting on a roof for days points to a sagging deck or a missing fall. Patching the membrane does not cure it.
Blocks and leaseholds
On managed buildings, roof repairs usually go through the managing agent or freeholder. We are happy to quote and report to them directly.
Access on taller buildings
Three- to seven-storey blocks need planned access and edge protection. That cost will be on the quote, not a surprise later.
Low-lying sites
The Environment Agency flood warning area for Portbury Wharf and the Gordano Valley explicitly includes the Marina. Roofs there are not affected by tidal flooding, but it is a reminder that rainwater from flat roofs needs a clear route away.
Flat roof questions
Is EPDM better than felt?
Each has its place. EPDM is a single sheet with few joints and copes well with movement. Modern torch-on and liquid systems are good too. We recommend what suits the roof and say why.
Can you walk on an EPDM roof?
For maintenance, yes. If you want to use it as a balcony or terrace it needs a walking surface on top.
Do you do green roofs?
Ask us. It depends on the structure underneath; we will look and tell you.
Is flat-roof work guaranteed?
Yes, under our 20 year written guarantee.
Sources: Portishead Community Character Statement (areas D, H and L); Environment Agency flood warning area Portbury Wharf and Common and Gordano Valley.
Flat roof leaking or holding water?
Free inspection and a written quote to repair or replace.