GRP fibreglass and EPDM flat roofing specialists in Box — extensions, garages and outbuildings. Correct drainage, proper upstand detailing, 25-year material guarantee. Free no-obligation quotes.
Tell us the job in 30 seconds. No pushy sales, no call-out fee.
📞 Call Now: 01249 247 076In short: Flat Roofing in Box: Flat roofing runs £900–£2,500 for a typical extension. We cover Box and the surrounding SN13 area with free quotes, no call-out fee, and a 10-year workmanship guarantee. Failing felt flat roofs are best replaced in GRP or EPDM rather than patched.
All flat roofing work across Box and surrounding Wiltshire — same local team, same standards, same guarantee as our Chippenham base.
Seamless, UV stable, 25-year material guarantee. Our standard recommendation for domestic extensions. Installed in one day on most standard roofs.
Get a quote →Better suited to large or complex roof shapes with significant thermal movement. 20-year material guarantee. Excellent performance on wide-span outbuildings.
Get a quote →Budget flat roofing option. Shorter lifespan than GRP or EPDM but appropriate where cost is the primary constraint. We advise honestly on expected service life.
Get a quote →Included on every flat roof replacement. We inspect boards before laying the new membrane — rotten or damaged deck is replaced as part of the same visit.
Get a quote →Ponding flat roofs have a fall problem, not just a membrane problem. We correct drainage falls as standard on every flat roof replacement — not just relay over the existing profile.
Get a quote →Sudden flat roof failure causing active water ingress. Same-day temporary seal available. Permanent GRP replacement scheduled within the week.
Get a quote →The By Brook valley creates high humidity and heavy tree canopy — moss growth rates are among the fastest in our Wiltshire coverage, and lead corrosion is accelerated by valley moisture. For flat roofing work in Box, this means specification choices that reflect the actual conditions rather than generic Wiltshire averages.
Bath stone AONB village with period cottages requiring lime mortar and matching stone materials throughout. We are 8 miles southwest from Box — 15 minutes — with no travel surcharge and same local knowledge that applies to every property type in this area.
Free quotes. No call-out fees. 15 minutes from Chippenham.
Failing felt flat roofs are best replaced in GRP or EPDM rather than patched in Box. Box is a Bath-stone village strung along the valley between Bath and Corsham — stone cottages, stone-slate and clay roofs, and steep valley-side plots. On this kind of stock, the common problems are heavy moss on shaded valley roofs, stone-slate slippage, and blocked valleys from the dense canopy — and knowing which you are dealing with is the difference between a lasting fix and money wasted.
Flat roofing calls from Box are predominantly on rear extensions of the period and modern fringe properties. The By Brook valley's moisture retention means flat roofs here accumulate moss and algae faster than on drier, higher ground — accelerating felt surface degradation. We replace with GRP as standard, which is moisture-resistant and easy to treat for biological growth.
Conservation area and AONB designations in Box don't typically constrain rear flat roof replacement, but visible flat roofs on listed buildings may need prior approval. We confirm planning status during the free survey before any specification is agreed.
We remove the old covering and inspect the deck for rot — the step most quotes skip.
We check and correct drainage falls so water runs off cleanly rather than ponding.
A fixed price covering deck repairs, membrane and trims, agreed before work starts.
GRP is laid wet and cures seamless; EPDM is bonded as one sheet. Trims and upstands dressed in.
The finished roof carries a 25-year material guarantee (GRP) plus our workmanship cover.
| Job | Typical duration |
|---|---|
| Small extension (GRP, up to 15m²) | 1–2 days |
| Standard extension (GRP) | 2–3 days |
| Garage roof (EPDM) | 1 day |
| Deck / board replacement | +half to full day |
| Larger / commercial flat roof | per assessment |
GRP needs dry conditions to cure; we won't lay fibreglass in rain, so winter jobs are weather-scheduled.
Box's stone cottages sit on steep valley plots with tight lane access, often requiring stone-slate matching and careful scaffold on the slopes. Pavement scaffold and skip permits in Box go through Wiltshire Council; on tight streets like the A4 through the village, Market Place, High Street we allow extra time for setup and access.
Flat roofing runs £900–£2,500 for a typical extension. Box pricing tracks Chippenham, adjusted for access on Box's stock.
| Job | Typical range | Notes |
|---|---|---|
| GRP small extension (up to 15m²) | £1,200–£1,800 | 25-year guarantee |
| GRP standard extension (15–25m²) | £1,800–£2,500 | Seamless fibreglass |
| EPDM standard extension | £900–£1,800 | Single bonded sheet |
| Garage roof (GRP or EPDM) | £800–£1,600 | Per garage |
| Deck / board replacement | £150–£400 | Where timber has gone soft |
| Larger / commercial flat roof | from £45/m² | Single-ply or GRP |
No deposit on jobs under £500. On larger flat roofs, no payment before materials are on site. VAT included. Payment on completion once tested and dry.
Covering SN13 and surrounding postcodes.
GRP carries a 25-year material guarantee and EPDM 20 years; our workmanship cover sits on top, and the deck and falls — which decide longevity — are guaranteed too.
A day or two of work over a single room, minimal internal disruption; we clear the old felt and all waste on completion. You do not need to stay home for external work.
EPDM can go on year-round; GRP needs a dry weather window. We temporary-weatherproof if rain interrupts a job. Box sits deep in the By Brook valley, so properties are shaded, damp-prone and slow to dry, with heavy tree cover.
"GRP flat roof replacement on extension — done properly, first time. Dry for two winters. Free quote was accurate and no hidden additions."
"Extension flat roof had been leaking for years. Previous roofer patched it twice. These stripped and replaced with GRP. Finally resolved."
"Garage flat roof replaced in EPDM — large complex shape, handled correctly. Clean job, good price."
GRP fibreglass up to 20m²: £1,200–£2,500. EPDM up to 20m²: £900–£1,800. Includes strip, deck inspection, drainage correction and installation. Free written quote — call 01249 247 076.
Box is 8 miles southwest — 15 minutes. No travel surcharge. Free surveys and quotes.
GRP fibreglass carries a 25-year material guarantee and significantly outlasts felt. It's seamless once cured, handles thermal cycling well, and doesn't suffer the joint failures common on felt. We recommend GRP over re-felting in almost all cases.
A standard single-storey extension flat roof up to 25m² is typically completed in one day. Larger or more complex roofs may take two days. We give an accurate timeline in every quote.
Yes — garages, outbuildings and garden buildings are a regular part of our flat roofing work in Box. Same specification and 25-year guarantee as domestic extensions.
If the roof is more than 20 years old and showing active failure, replacement is almost always more cost-effective than repair. We survey and advise honestly — we won't recommend replacement if targeted repair genuinely meets the situation.
GRP fibreglass carries a 25-year material manufacturer's guarantee plus our own 10-year workmanship guarantee. EPDM carries a 20-year material guarantee. Both are provided in writing on completion.
No call-out fees. No obligation. Local roofer covering all of Wiltshire.
01249 247 076Last updated: August 2026