GRP fibreglass, EPDM rubber and felt flat roofing for garages, extensions and outbuildings across Cheltenham and Gloucestershire. Long-lasting, properly drained, and guaranteed for 25+ years. Free surveys and written quotes.
Tell us the job in 30 seconds. No pushy sales, no call-out fee.
📞 Call Now: 0124 235 2251Cheltenham receives higher-than-average annual rainfall from weather systems funnelling up the Severn Vale. Flat roofs here need to be properly specified and correctly drained. We install three proven systems.
Our most-installed system. Seamless, rigid, highly waterproof and low-maintenance. 25+ year design life. Ideal for garages and rear extensions across Cheltenham. The industry standard for new flat roofs. From £80/m².
Get a Quote →Highly flexible synthetic rubber membrane ideal for larger flat roofs. 30+ year life, excellent UV resistance and handles Gloucestershire's freeze-thaw cycles well. Single-piece installation on suitable roofs. From £70/m².
Get a Quote →Three-layer SBS modified bitumen systems for large commercial-grade flat roofs. More economical per m² on large areas. 15–20 year life depending on specification. From £50/m².
Get a Quote →Blistered felt, split seams or localised GRP failure can often be repaired rather than replaced. We assess honestly and repair where it makes sense. Emergency weatherproofing available same-day.
Get a Quote →Free survey and written quote across Cheltenham.
Flat roofs on Cheltenham extensions, dormers and garages usually fail in predictable ways. Knowing whether you need a patch, a re-cover or a full warm-deck rebuild saves money and stops you paying twice.
When it is not the answer: If your existing flat roof is a sound single-ply or GRP system with an isolated fault, a localised repair is enough — you don't need to re-cover the whole roof, and any roofer who insists otherwise is overselling. Read the full guide.
Cheltenham's position at the foot of the Cotswold escarpment means the town receives consistent westerly airflow loaded with moisture from the Severn estuary and Welsh uplands. Annual rainfall is notably higher than the national average, and freeze-thaw cycles through winter put flat roof coverings under significant stress. Poorly specified or ageing felt systems fail quickly in these conditions — blistering in summer heat, then splitting when the blister freezes in winter.
The large number of 1960s–80s garage and extension flat roofs across Cheltenham's Hester's Way, Benhall and suburban fringe are mostly on their second or third felt covering and increasingly showing deck deterioration. When deck boards are sound, a GRP overlay is the most cost-effective solution. When boards show rot, a full deck replacement before GRP is the correct specification.
Proper falls are critical. A minimum 1:80 fall to outlets is required by BS 6229 — many older flat roofs across Cheltenham have inadequate drainage that causes ponding and accelerated covering failure. We assess drainage as part of every flat roof survey and correct falls where needed.
Guide prices for common flat roof projects in Cheltenham. Your written quote will be fixed before work starts.
Approx 15–20m². Full GRP fibreglass installation including deck inspection, coving and drip edge.
Approx 20–35m². Kitchen, utility or living room extension flat roof. Drainage outlets and edge trim included.
35–60m². EPDM single-piece installation on larger areas. Falls corrected where needed.
Localised GRP patch, split seam repair or felt overlay on sound decks. Dependent on size and system.
We assess the covering, the falls and the deck condition — a wet deck under sound-looking felt is the commonest hidden problem — and recommend repair, re-cover or a warm-deck rebuild.
A fixed price for the specified system (EPDM rubber, GRP fibreglass or torch-on felt), including any deck renewal, insulation upgrade and new trims and outlets.
Flat-roof jobs are usually a matter of days; we book a firm date and pick a dry window where the system needs it.
We strip the failed covering, renew any wet deck, upgrade to a warm-deck build-up where regulations require, and install the new membrane with properly formed upstands, trims and outlets.
Debris and old felt cleared, the new roof and its drainage checked, and the written guarantee handed over.
| Job | Typical duration |
|---|---|
| Small flat-roof repair | 2–4 hours |
| Garage or porch re-cover | 1 day |
| Extension flat roof (EPDM/GRP) | 1–3 days |
| Warm-deck rebuild with deck renewal | 2–4 days |
GRP and torch-on systems need dry conditions to cure or bond, so we watch the forecast; EPDM is more weather-tolerant to install.
Ground-floor flat roofs on Cheltenham extensions and garages are often reached from a tower or ladder; scaffold is only needed for higher dormer or first-floor flat roofs. Scaffold is specified for: first-floor flat roofs, dormers, or where edge protection is required at height - always itemised in your written quote, never a hidden extra, and we arrange it.
Cheltenham's Regency terraces in Montpellier and Lansdown have railings, lightwells and shared party walls that limit rear access, so pavement scaffold and skip space usually need a permit. Pavement scaffold and skip permits go through Cheltenham Borough Council; allow a few working days on streets like Montpellier Street, the Suffolks, the terraces off St Paul's Road where space is tight.
| Job | Typical range | Notes |
|---|---|---|
| Flat-roof leak repair | £150–£450 | Localised patch or seam repair |
| Garage/porch re-cover (felt) | £800–£1,800 | Torch-on felt system |
| Extension flat roof (EPDM) | £1,800–£4,000 | Single-ply rubber, one-piece |
| Extension flat roof (GRP) | £2,000–£4,500 | Fibreglass, seamless finish |
| Warm-deck rebuild + insulation | £3,000–£6,000 | Meets Building Regs for habitable rooms |
Worked example: A one-piece EPDM re-cover on a 20m² rear-extension flat roof in Leckhampton, including new trims and a renewed outlet: around £2,600.
No deposit on flat-roof repairs under £500. Larger re-covers are invoiced on completion or in two stages, never before materials are on site.
The flat-roof installation carries a written 10-year workmanship guarantee, and quality EPDM and GRP systems carry manufacturer warranties of 20 years or more on top.
If a fault appears in covered work, we come back and put it right. No quibbling, no re-charge.
Flat-roof work is contained and quiet; torch-on felt involves controlled heat work, which we carry out to safe hot-works practice with the area protected. 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 and felt need a dry, mild window to cure properly, so we plan those around the weather rather than rushing them. Cheltenham's sheltered vale position brings damp Cotswold-edge autumns and heavy leaf fall from the town's many mature trees, which keeps north-facing slopes slow to dry.
"Had the rear extension and integral garage both done in GRP in the same week. Really efficient, everything was explained clearly, and the finish is excellent. Not a drip since — and we've had some serious Cheltenham rain."
"Third roofer we asked and the only one who was honest that the deck boards needed replacing rather than just a felt overlay. Glad we went with their recommendation — the GRP result is far better than I expected."
"Large flat roof over the back of the house, EPDM. They corrected the drainage falls which three previous roofers had missed entirely. No ponding at all now after the first heavy rain. Very thorough."
A standard single garage flat roof in Cheltenham costs £800–£1,500 for GRP fibreglass. A rear kitchen extension flat roof typically costs £1,500–£3,000 depending on size. Larger roofs over multiple extensions are quoted individually. All quotes are free and written.
GRP fibreglass is our most recommended system for Cheltenham — it handles the town's high annual rainfall well, has a 25-year design life, and requires minimal maintenance. EPDM rubber is a good alternative for larger areas. We'll recommend the right system for your property after a free survey.
A correctly installed GRP fibreglass flat roof lasts 25+ years. EPDM lasts 30+ years with minimal maintenance. Old felt systems typically last 10–15 years and are the most common replacement we carry out across Cheltenham's garage and extension stock.
Yes. If the existing deck is sound and the covering is locally failed rather than at end of life, repair can be cost-effective. We'll assess this at the free survey and tell you honestly whether repair or full replacement makes more sense.
Signs include ponding water not draining within 48 hours, visible cracking or bubbling, soft spongy areas, damp patches on ceilings below, or any felt roof over 15 years old.
Our GRP flat roofs carry a 20-year manufacturer guarantee and our 10-year workmanship guarantee. EPDM systems carry a 15-year material guarantee. All guarantees are in writing and transferable.
Yes. We install build-ups suitable for sedum and wildflower green roofs on flat extensions. These require a reinforced deck and specific waterproofing layers. Increasingly popular in conservation areas where planners prefer a less visually impactful roof finish.
Free survey and written quote across Cheltenham and Gloucestershire. GRP fibreglass specialists.
0124 235 2251Area-specific flat roofing guides — local pricing, housing stock profiles and what systems work best in each location.
We provide flat roofing across Cheltenham and the surrounding Gloucestershire towns. Tap your area for local details, or call 0124 235 2251.