GRP fibreglass, EPDM rubber and built-up felt flat roofing for extensions, garages and outbuildings across Chippenham and Wiltshire. Long-lasting solutions with proper drainage and free no-obligation quotes.
Flat roofs are only as good as their drainage and membrane. We install proper falls, correct edge detailing and modern membrane systems that last — not the quick fixes that are back leaking in three years.
The most durable flat roofing option for Chippenham extensions and garages. GRP is seamless, waterproof, and carries a 25-year material guarantee. Installed in one continuous laminate with no joins for water to find.
Get a quote →Single-ply EPDM membrane is ideal for large flat roof areas. Lightweight, UV stable and highly resistant to the temperature extremes of Wiltshire winters and summers. Properly bonded with no torching required.
Get a quote →Three-layer built-up felt is a reliable and cost-effective option for garages and outbuildings. We use high-performance mineral-capped felt with full torch-on application — not laid cold over old felt.
Get a quote →Most flat roof failures in Chippenham trace back to poor drainage — insufficient fall, blocked outlets, or raised upstands. We assess and correct drainage design as part of every installation.
Get a quote →Blistering, ponding, splits or failing upstands repaired correctly. We identify the source of failure before patching — saving you money on recurring temporary repairs.
Get a quote →Where a flat roof is beyond repair, full strip and replacement is more cost-effective long term. We remove all existing layers back to deck, replace any rotted decking boards, and install the appropriate modern membrane system.
Get a quote →No call-out fees. Free quotes. Same-day emergency cover.
The highest concentration of flat roof work we do in Chippenham is on rear extensions — particularly on Pewsham properties from the 1990s and 2000s where the original felt flat roofs are now 20–30 years old. Ponding is the most common complaint, caused by insufficient fall designed into the original extension. We correct the drainage issue as part of the re-roofing rather than applying new membrane over the same drainage problem.
On older Chippenham properties — Victorian and Edwardian terraces where additions to the rear of the property have flat roofs — we often find torch-on felt applied over original mineral felt. Where the underlying deck is sound, we strip to deck, check for rot, and install GRP or EPDM over a new plywood deck where required.
GRP fibreglass (up to 20m²): £1,200–£2,500. EPDM rubber (up to 20m²): £900–£1,800. Felt re-roof (up to 20m²): £600–£1,200. Larger areas are priced per m². All prices include strip, deck inspection, drainage assessment and installation. Free written quote before any work starts.
"Extension flat roof had been patched twice and still leaked. Went for GRP this time — it's been two winters now with absolutely no issues. The drainage correction they did at the same time has stopped the ponding we'd had since the extension was built."
"Garage roof was completely sodden — three layers of old felt with water between each. Stripped back to deck, replaced three boards and installed new three-layer torch-on felt. Solid job, fair price, cleaned up perfectly."
"Large L-shaped extension flat roof done in EPDM. Impressed by how neat the upstand detailing is — previous quotes hadn't even mentioned it. No issues after the first winter."
See our full breakdown of a flat roof cost in Chippenham prices in Chippenham — honest 2026 ranges, worked examples on named local estates, and what moves the price.
See also: Velux & skylights, commercial flat roofing.
GRP fibreglass is our first recommendation for domestic extensions in Chippenham — it's seamless, durable, and carries a 25-year material guarantee. EPDM is ideal for larger areas. The right choice depends on your roof size, shape and budget — we'll advise in the free survey.
GRP fibreglass: 25–40 years. EPDM rubber: 20–30 years. Good quality felt: 15–20 years. The most common cause of early failure is poor drainage design rather than membrane failure — we correct drainage as standard on every installation.
Depends on the condition of the deck and existing membrane. Isolated blisters or splits on a relatively new felt roof can be patched effectively. Where the membrane is 20+ years old or the deck is wet, replacement is more cost-effective. We assess and give you an honest recommendation.
Standard flat roof replacement like-for-like doesn't need planning permission. If you're adding a new extension with a flat roof, permitted development rules apply. We'll advise during the survey.
GRP fibreglass carries a 25-year material guarantee and regularly exceeds 40 years in service when correctly installed. The critical factors are proper deck preparation, correct resin formulation for ambient temperature, and correct upstand detailing. Shortcuts in any of these reduce service life significantly.
In some cases yes — usually on extensions where head height allows. It requires a structural assessment and planning consideration in some cases. We can advise on feasibility during the free survey, though pitched conversion work involves a builder as well as a roofer.
GRP fibreglass is rigid, seamless once cured, and has excellent resistance to foot traffic and point loads — ideal for most domestic extensions. EPDM rubber is more flexible, better suited to very large or complex-shaped roofs where thermal movement is a factor. We recommend the right system for your specific roof geometry.
No call-out fees. No obligation. Honest pricing from a local Chippenham roofer.
01249 247 076