Flat Roof Installation and Repair Across East London, North London and Essex
EPDM rubber, fibreglass GRP, torch-on felt and single-ply membrane systems — installed and repaired by FNB Roofing And Building across every property type in the area.
Find Us On


FLAT ROOFING SPECIALISTS · LONDON & ESSEX
Flat roofs that don’t leak — for thirty years, not three.
Flat roofs feature on nearly every property type in the area — rear extensions, dormer cheeks, porch roofs, garage roofs, outbuildings, and the increasingly common full-width kitchen extensions seen across Walthamstow, Hackney and the surrounding boroughs. They are also the part of a property most prone to leaks if the original installation cut corners on falls, upstands or detailing. FNB Roofing And Building installs and repairs flat roofs of every type, working in felt, EPDM rubber, fibreglass GRP and single-ply membrane systems — every project guaranteed in writing and backed by £1 million of public liability cover.
Flat Roof Systems We Install
Every membrane has a sweet spot. The right one for your property depends on use, exposure, budget and how long you want the covering to last before it’s looked at again.
15–20 YEAR LIFESPAN
Torch-On Felt
The traditional UK system. Modern three-layer high-performance felt remains the most cost-effective choice for garages and outbuildings.
30+ YEAR LIFESPAN · MOST POPULAR
EPDM Rubber
Single-sheet rubber membrane — now the leading choice for domestic extensions in London. No fading, no shrinkage, no maintenance beyond clearing debris.
SEAMLESS · FULL WARRANTY
Fibreglass GRP
A seamless, hard-wearing finish backed by full manufacturer warranty. Particularly suited to balconies and terraces that see foot traffic.
COMMERCIAL · LARGE SPANS
Single-Ply Membrane
Wide-format sheets with hot-air welded seams. Suited to larger commercial installations and complex domestic geometries with very long service life.
Note: we do not work with green roofs.
COMMON FLAT ROOF PROBLEMS IN LONDON
The capital’s housing stock is hard on flat roofs.
Rear extensions sit low to the ground and often beneath trees, attracting debris and prolonged damp conditions. Older felt roofs on garages — dating from the 1970s and 1980s — are routinely well past their service life. And parapet wall junctions on terraced properties, where the flat roof meets a neighbour’s brickwork, are a frequent point of historic leak failure due to inadequate original detailing.
Repairs are quoted honestly and not offered as a substitute for replacement where the underlying system has clearly reached the end of its life. Where a flat roof has been repeatedly patched and is more patch than original system, replacement is usually the more economical route. An honest assessment is provided either way.
The most common faults we address:
- Ponding water and inadequate falls
- Blistering and lifting felt
- Failed EPDM seams or shrinkage at upstands
- GRP cracks at stress points, particularly at angle changes and upstand bases
- Failed lead flashing where the flat meets a pitched roof
- Splits at parapet wall junctions
- Deck rot beneath a long-failed covering
What’s Included in a Flat Roof Installation
A correctly specified flat roof is more than the visible membrane. Every installation covers the following as standard.
PREPARATION
- ✓ Strip-out and responsible disposal of the existing covering
- ✓ Deck inspection, with timber replacement where rot is identified
- ✓ Vapour control layer where specified
INSTALLATION
- ✓ Insulation upgrade where current Building Regulations apply
- ✓ Membrane installation to manufacturer specification
- ✓ All upstands, drips, eaves and verge detailing
FINISH & COVER
- ✓ Lead flashing at any abutting walls
- ✓ Outlet and rainwater connection
- ✓ Manufacturer warranty cover where applicable
How a Typical Flat Roof Project is Delivered
Most flat roof projects follow a clear four-stage process, designed to keep you fully informed from first call to final sign-off. Most domestic installations are completed in two to four working days, weather permitting.
01
Survey and Specification
A site visit is arranged at a convenient time. The condition of the existing roof, deck and falls is recorded, photographic evidence supplied where useful, and the most suitable membrane recommended on the basis of use, exposure and budget.
02
Itemised Written Quotation
A written quotation is issued covering materials, labour, access, waste disposal and any deck repairs anticipated — providing a clear basis for like-for-like comparison against competing quotes.
03
Programmed Installation
Works are scheduled at a time that suits the client and carried out by our own tradesmen rather than subcontracted. Most domestic flat roof installations are completed in two to four working days, weather permitting.
04
Sign-Off, Guarantee & Aftercare
A final inspection confirms satisfaction. Workmanship is guaranteed in writing, and manufacturer warranties on the chosen membrane apply in addition — typically 15 to 25 years depending on specification.
Manufacturer warranties up to 25 years
Workmanship guaranteed in writing, with membrane manufacturer cover layered in addition.
£1m public liability insured
Full cover for the property, our workforce and any third parties present during the works.
Local — not a subcontractor
Operating from Walthamstow with a long trading history. The team you meet is the team that delivers the work.
Areas We Cover for Flat Roofs
Flat roof installations and repairs are carried out across East London, North London and Essex, including Waltham Forest, Hackney, Haringey, Redbridge, Newham, Islington, Enfield and the surrounding boroughs, alongside postcodes throughout the E, N, IG and RM regions.
E1–E18
N1–N22
IG & RM
Frequently asked questions about Flat Roofs
Common questions on systems, lifespan, repair vs replacement, and how a typical project runs.
Which flat roof system is right for my extension?
EPDM rubber is the default recommendation for most domestic extensions in London — it carries a 30+ year service life, no seams across a typical extension and effectively no maintenance burden. GRP is preferable where the roof will see foot traffic, such as a balcony. Felt is the most cost-effective choice for garages and outbuildings. Single-ply is generally only specified on larger or commercially-scaled installations. The right answer is fully dependent on your roof — which is why the survey is free.
How long does a flat roof installation take?
Most domestic flat roof installations are completed in two to four working days, weather permitting. Larger extensions, balconies or roofs requiring significant deck replacement may run longer. A realistic timeline is given as part of the written quotation.
Can my flat roof be repaired, or does it need replacing?
Repairs are quoted honestly and not offered as a substitute for replacement where the underlying system has clearly reached the end of its life. Where a flat roof has been repeatedly patched and is more patch than original system, replacement is usually the more economical route. An honest assessment is provided either way — no pressure either direction.
What warranties come with a new flat roof?
Workmanship is guaranteed in writing by FNB Roofing And Building, and the manufacturer warranty on the chosen membrane system applies in addition. Depending on specification, this typically runs between 15 and 25 years.
Do you install green roofs?
No — green roofs are outside our scope. For all other flat roof systems — EPDM, GRP, felt and single-ply membrane — we install and repair across East London, North London and Essex.
Are quotes free, and is there any obligation?
Yes — quotes are completely free. There is no charge for the site visit, no obligation to proceed, and no follow-up sales pressure. Most projects can be priced within a few working days of initial contact.
Are you insured?
Every project is backed by £1 million of public liability insurance as standard, ensuring full cover for the property, our workforce and any third parties present during the works.
“Storm took half our flat roof off on a Sunday night. FNB had it watertight by Tuesday and re-laid in EPDM the following week. Faultless.”
M Williams
Hackney, E8
“New EPDM on a full-width kitchen extension. Properly dressed upstands and lead at the abutment — three winters in and not a drop inside.”
K Ahmed
Leyton, E10
“GRP balcony to the rear of a first-floor flat. Seamless finish, walked on daily, holding up perfectly. Honest pricing from start to finish.”
D Roberts
Walthamstow, E17
Request a Flat Roof Quote
Contact us for a free survey and written estimate. There is no obligation to proceed and no charge for the quotation itself.
Why FNB for your flat roof?
- ✓ EPDM, GRP, felt & single-ply specialists
- ✓ Manufacturer warranties up to 25 years
- ✓ £1m public liability insured
- ✓ Workmanship guaranteed in writing
- ✓ Same-week emergency response
- ✓ All works delivered in-house
