- Guide price
- £2,950–£5,150
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Cambridgeshire at a glance
- Largest towns
- Peterborough, Cambridge, Wisbech, St Neots
- Postcode areas
- CB, PE
- Building control
- Peterborough City Council, Cambridge City Council, Fenland District Council and 2 other councils
- Neighbouring areas
- Northamptonshire · Bedfordshire · Hertfordshire · Suffolk
- Guide price region
- East of England (+5% on West Midlands rates)
How much does a flat roof replacement cost in Cambridgeshire?
Guide prices including VAT at East of England 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 | £2,950–£5,150 |
| Single garage (18 m²), torch-on felt | £1,600–£2,750 |
| Extension (20 m²), GRP, new deck + insulation | £3,150–£5,650 |
| Single garage (18 m²), EPDM rubber | £1,700–£2,950 |
Which flat roofs are common in Cambridgeshire?
Flat roofs in Cambridgeshire sit on low-rise post-war blocks of flats, terraced streets with flat-roofed rear kitchens and bathrooms and lock-up garage blocks on estates. The East of England is the driest part of Britain, with parts of the Anglian region around 630 mm a year, so summer heat and UV, not rainfall, do most of the ageing on a felt roof. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in England
Replacing more than half of a roof over a heated room usually counts as renovating a thermal element, so it is insulated to current standards and notified to building control. Renovated roofs over heated rooms are insulated to around 0.16 W/m²K where that's feasible, and new extension roofs are built to 0.15 W/m²K. In Cambridgeshire the application goes to Peterborough City Council, Cambridge City Council, Fenland District Council and 2 other councils. More on the rules.
How long does it take to replace a flat roof?
A garage or single-storey extension roof is usually stripped and re-covered in one to three working days; larger, higher or more detailed roofs take longer. Weather sets the pace, because the deck must be dry before insulation and membrane go down.
We strip only as much as can be made weathertight that day, so the roof is never left open overnight. Expect noise and some vibration during the strip, a skip on the drive (or on the road with a permit) and ladders or a tower against the house. Rooms below stay usable, though it helps to clear shelves near the ceiling. Resin systems such as GRP smell strongly while they cure, so keep nearby windows closed that day. Two-storey roofs need scaffold, which goes up before we start and comes down after sign-off.
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.
Which towns in Cambridgeshire do we cover?
Flat roof replacement in Cambridgeshire: questions
Which towns in Cambridgeshire do you cover?
All of Cambridgeshire. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a flat roof replacement cost in Cambridgeshire?
£2,950–£5,150 for a 20 m² extension roof in EPDM with a new deck and insulation, at East of England guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which postcode areas do you cover in Cambridgeshire?
All of Cambridgeshire, including the CB, PE postcode areas. Send your full postcode and we'll confirm.
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.
What time of year is best for a flat roof replacement?
Late spring to early autumn gives the most reliable dry spells, but a roof can be replaced in any season when the forecast allows. Adhesives and resins have minimum application temperatures, so winter work is planned around mild, dry days.
What guarantees come with a replacement roof?
Every re-roof comes with a written workmanship guarantee, with the length set out in your quote. Manufacturer material guarantees are available on many systems and we register them for you where the system allows; ask about insurance-backed options too.
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