Complete flat roof replacement in GRP fibreglass or EPDM rubber. 25-year material guarantee. Canterbury and East Kent specialists. No more patching — replace properly. Free surveys.
A failing flat roof is usually ageing felt that has cracked, blistered or split at a seam or upstand. Here is how to tell whether yours needs a patch or a recover.
When it is not the answer: If a modern GRP or EPDM roof has a single localised puncture, a patch is enough — you do not need a full recover. Read the full guide.
We locate the failure and check the deck and the falls beneath the covering.
Fixed price for patch or full recover in GRP or EPDM, deck repair included if needed.
Most flat roofs are recovered in one visit; larger areas booked in.
Old covering off, deck repaired, new system laid with proper falls to the outlet.
Site cleared and the roof guaranteed.
| Job | Typical duration |
|---|---|
| Garage / small outbuilding | 1 day |
| Single-storey extension | 1–2 days |
| Dormer flat roof | 1 day |
| Large wrap-around extension | 2–3 days |
GRP needs a dry spell to cure; we schedule around the forecast and never lay onto a wet deck.
Most flat roofs are low and reached from a tower; scaffold only where the flat roof is at height or wraps a two-storey return. Scaffold is specified for: first-floor or wrap-around flat roofs, or where edge protection is needed - always itemised in your written quote, never a hidden extra, and we arrange it.
Canterbury’s medieval core and the Victorian terraces off Wincheap and St Dunstan’s often mean tight frontages, shared rear access and conservation-street constraints, so scaffold and skip placement take planning. Pavement scaffold and skip permits go through Canterbury City Council; allow a few working days on streets like Palace Street, Burgate, St Dunstan’s Street where space is tight.
GRP · EPDM · 25-year material guarantee · Canterbury specialists
Canterbury has a large volume of flat roof extensions — the rear kitchen and dining room additions that were added to Victorian and Edwardian terraces throughout the 20th century. Many of these were last recovered in felt in the 1970s or 1980s and are now well beyond their design life. The Stour valley's above-average rainfall and humidity means felt flat roofs in Canterbury deteriorate faster than the same specification on drier inland sites, and repeated patching becomes more expensive than a proper replacement within a few years.
GRP fibreglass is the material we specify for the majority of Canterbury flat roof replacements. Its seamless single-piece installation eliminates the joint failures that are the primary cause of felt leaks. It handles Canterbury's rainfall loading without pooling. The 25-year manufacturer's material guarantee provides genuine long-term protection. On larger flat roof sections — typically over 40m² — we assess EPDM rubber as an alternative, which can be more cost-effective on very large areas while still providing a 20-year guarantee.
Rear extension flat roofs on Victorian and Edwardian terraces across Wincheap, St Dunstan's and Hales Place. Garage flat roofs on post-war and 1960s–70s properties in Barton, Rough Common and Thanington. Single-storey rear additions on semi-detached housing throughout the Canterbury CT1/CT2 area. Dormer flat roof sections on Victorian and Edwardian loft conversions. Bay window top sections on period properties throughout the city.
“Felt flat roof on the rear kitchen extension had been patched three times. Canterbury Roofing replaced it in GRP. It has been bone dry through two wet Canterbury winters. Excellent work.”
“Garage flat roof was completely saturated — the felt had gone. Full GRP replacement in a day. The difference in drainage is obvious, no more pooling water.”
“Large flat roof over the Victorian rear addition. They assessed it properly, recommended GRP over the quote they gave for EPDM on the larger area. Honest advice and a clean finish.”
| Job | Typical range | Notes |
|---|---|---|
| Garage / outbuilding | £1,200–£2,000 | EPDM or GRP |
| Single-storey extension | £2,000–£4,000 | GRP for complex shapes |
| Large / wrap-around | £3,000–£6,000 | GRP seamless |
| Dormer flat roof | £800–£2,000 | Incl. lead junctions |
| Felt strip & deck repair | from £300 | Added if deck wet |
Worked example: A 12m² rear kitchen extension off Wincheap recovered in GRP with a soft-deck patch: about £2,600.
No deposit on small flat-roof repairs. Staged payment on larger recovers, materials on site first.
Covering CT1, CT2, CT3, CT4 and surrounding postcodes.
GRP and EPDM systems carry a 10-year workmanship guarantee and 20–35 year material life — far beyond the felt we replace.
If a fault appears in covered work, we come back and put it right. No quibbling, no re-charge.
Quiet, quick work confined to the flat area — minimal mess and usually done in a day. You do not need to stay home for external work - we just need power and access agreed in advance.
EPDM can go on in most conditions; GRP needs dry, so we watch the forecast. The Stour valley holds humidity, so drying times lengthen in autumn and moss returns fast on north-facing and tree-shaded roofs.
A full GRP fibreglass flat roof replacement on a standard rear extension in Canterbury typically costs £900–£2,200 depending on area. Garage flat roofs are £700–£1,800. Large flat roof sections over single-storey rear additions on Canterbury's Victorian and Edwardian terraces typically run £1,200–£3,000. GRP carries a 25-year material guarantee. EPDM rubber is a slightly lower-cost option at £700–£1,800 for the same extension size with a 20-year guarantee.
GRP fibreglass is the recommended specification for Canterbury. It handles the above-average Stour valley rainfall better than felt, its seamless installation means no joints to fail, and it is significantly more durable in Canterbury's damp conditions. EPDM rubber is a solid alternative for larger flat roof areas where GRP installation becomes more complex. We do not recommend felt as a long-term solution on Canterbury properties and will not install it as a new roof covering.
A standard rear extension flat roof in Canterbury takes 1–2 days for GRP installation including preparation, resin application and curing time. Larger sections or those requiring structural repairs take longer. We provide a realistic timeline in the quotation.
Canterbury's Stour valley position creates above-average annual rainfall and humidity compared to surrounding higher ground. Flat roofs in Canterbury collect standing water more readily than pitched surfaces, and the combination of high rainfall and valley humidity accelerates felt membrane degradation — particularly on the large number of 1970s and 1980s extension flat roofs across the city's housing stock. GRP or EPDM replacement is the correct long-term solution.
In most cases yes. Flat roof replacement is carried out from the exterior and does not require internal access unless there is structural damage to the roof deck itself, which we assess on the free site visit. We protect garden areas and clear all debris as part of the installation.
No call-out fees. No obligation. An honest quote from a local Canterbury roofer who turns up when they say they will.
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