Farnborough at a glance
- Postcode districts
- GU14
- Population
- about 60,652 (GeoNames)
- Council area
- Rushmoor Borough Council
- Building approval
- Rushmoor Borough Council building control, or a registered building control approver
- Nearest main town
- Bracknell, about 8 miles
- Guide price region
- South East (+10% on West Midlands rates)
When should a flat roof in Farnborough be replaced?
A sensible moment to replace a flat roof in Farnborough is when other work is planned on the house, such as a kitchen refit below, new windows or a loft conversion. Doing the roof first protects the new work, and it is the natural time to upgrade insulation to the level the regulations expect for a renovated roof.
Farnborough's flat roofs are mostly on bungalows with flat-roofed side extensions and dormers, with plenty on newer estates where the first extension roofs are now being replaced too. Much of the South East sits in the drier Thames catchment at roughly 730 mm of rain a year, so the usual failures are at joints, upstands and outlets rather than from sheer volume of rain.
How much does a flat roof replacement cost in Farnborough?
Guide price in Farnborough: £3,100–£5,350 for a 20 m² extension roof in EPDM with a new deck and insulation, including VAT at South East rates. 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 | £3,100–£5,350 |
| Single garage (18 m²), torch-on felt | £1,650–£2,900 |
| Extension (20 m²), GRP, new deck + insulation | £3,300–£5,900 |
| Single garage (18 m²), EPDM rubber | £1,750–£3,100 |
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?
- New deck, firrings and warm-roof insulation where needed
- New membrane, upstands, edge trims and outlets
- Building control handled where needed, plus a written workmanship guarantee
- Fixed written quote listing the full build-up
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 Farnborough: questions
Do you cover Farnborough?
Yes. Farnborough is part of our Hampshire coverage, including postcode districts GU14. 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 Farnborough?
Where the work needs approval it goes to Rushmoor Borough 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 Farnborough?
£3,100–£5,350 for a 20 m² extension roof in EPDM with a new deck and insulation, at South East 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 new flat roof be better insulated than the old one?
If it is over a heated room, yes. A full replacement usually has to be upgraded towards current insulation levels where feasible, and we build it as a warm roof with the insulation above the deck.