Westbury at a glance
- Postcode districts
- BA13
- Population
- about 16,989 (GeoNames)
- Council area
- Wiltshire Council
- Building approval
- Wiltshire Council building control, or a registered building control approver
- Nearest main town
- Bath, about 11 miles
- Guide price region
- South West (+3% on West Midlands rates)
When should a flat roof in Westbury be replaced?
A flat roof in Westbury is often worth replacing because it is the weak point of the building: heat escapes through an uninsulated deck, rooms below are cold in winter and hot in summer, and condensation marks the ceiling. A warm-roof replacement deals with comfort as well as leaks, so it is worth considering before the roof fails outright.
Westbury's flat roofs are mostly on shops with flat-roofed rear stores below flats, with plenty on 1930s semis with flat-roofed garages and kitchen extensions too. The South West averages roughly 1,260 mm of rain a year and many roofs face wind off the Atlantic, so we specify fixings and edge details for wind uplift as well as drainage.
How much does a flat roof replacement cost in Westbury?
At South West guide rates, a 20 m² extension roof in EPDM with a new deck and insulation comes to £2,900–£5,050 including VAT. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £2,900–£5,050 |
| Single garage (18 m²), torch-on felt | £1,550–£2,700 |
| Extension (20 m²), GRP, new deck + insulation | £3,100–£5,550 |
| Single garage (18 m²), EPDM rubber | £1,650–£2,900 |
Should I overlay my old flat roof or strip it fully?
Strip it fully if the deck is soft, the insulation is wet or the falls are wrong; an overlay only suits a dry, sound roof that already drains well. Covering a wet roof traps the moisture, and rot carries on out of sight.
An overlay also raises the roof level, eating into upstand height at walls and door thresholds, and every layer adds weight. In England, a covering that adds 15% or more to the roof's weight needs building control approval. Signs it is time to replace rather than repair:
- ponding that lingers long after rain
- blisters, cracking or crazing across wide areas
- bare bitumen where the mineral chippings have gone
- split laps and lifted upstands or flashings
- damp ceilings, or a deck that has gone soft
- leaks that return after each repair
A single defect on an otherwise dry roof can usually be put right with a repair. If you're unsure, a survey settles it, and our guides to overlay or strip and repair or replace go further.
What's included?
- Fixed written quote listing the full build-up
- Strip-out of the old covering, with waste and skip
- New membrane, upstands, edge trims and outlets
- New deck, firrings and warm-roof insulation where needed
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
Flat roof replacement in Westbury: questions
Do you cover Westbury?
Yes. Westbury is part of our Wiltshire coverage, including postcode districts BA13. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Westbury?
Where the work needs approval it goes to Wiltshire Council building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a flat roof replacement cost in Westbury?
£2,900–£5,050 for a 20 m² extension roof in EPDM with a new deck and insulation, at South West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Is VAT charged on a flat roof replacement?
Yes, roof replacement is standard-rated at 20%, and an insulated replacement is treated as a single supply. Our guide prices already include VAT.
Will a replacement make my roof higher?
Usually a little, if insulation is added above the deck. We check door thresholds, window sills, upstands and wall flashings at survey so the new level works.