Watford at a glance
- Postcode districts
- WD1, WD17, WD18, WD19, WD24, WD25
- Population
- about 125,707 (GeoNames)
- Council area
- Watford Borough Council
- Building approval
- Watford Borough Council building control, or a registered building control approver
- Nearest main town
- Slough, about 13 miles
- Guide price region
- East of England (+5% on West Midlands rates)
When should a flat roof in Watford be replaced?
Selling or letting a property in Watford can also prompt a replacement. A buyer's surveyor will usually flag a flat roof near the end of its life, and a recent replacement with written workmanship and material guarantees answers that question before it turns into a negotiation point.
Around Watford, flat roofs are common on bungalows with flat-roofed side extensions and dormers and on terraced streets with flat-roofed rear kitchens and bathrooms. 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.
How much does a flat roof replacement cost in Watford?
At East of England guide rates, a 20 m² extension roof in EPDM with a new deck and insulation comes to £2,950–£5,150 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 | £2,950–£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 system should I replace my flat roof with?
The right system depends on the roof's size, shape, use and number of details, so no single material suits every roof. These are the usual starting points:
- EPDM rubber suits simple, rectangular roofs, where one sheet can often cover the area with few or no joins.
- GRP fibreglass suits roofs with many corners, rooflights or edges, and gives a rigid surface for occasional maintenance traffic.
- Torch-on felt is a layered, hard-wearing system that keeps the cost down on larger or plain roofs.
- Liquid-applied systems handle awkward details and can overlay a sound existing surface.
- Single-ply and mastic asphalt are more usual on commercial roofs, blocks and terraces.
We recommend a system at survey and explain why. Our EPDM vs GRP vs felt guide sets out the trade-offs if you want to compare first.
What's included?
- New membrane, upstands, edge trims and outlets
- Fixed written quote listing the full build-up
- Strip-out of the old covering, with waste and skip
- 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?
- Bushey · 2 mi
- Rickmansworth · 4 mi
- Borehamwood · 5 mi
- St Albans · 7 mi
- Hemel Hempstead · 7 mi
- Chalfont Saint Peter · 8 mi
Flat roof replacement in Watford: questions
Do you cover Watford?
Yes. Watford is part of our Hertfordshire coverage, including postcode districts WD1, WD17, WD18, WD19, WD24, WD25. 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 Watford?
Where the work needs approval it goes to Watford 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 Watford?
£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.
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.
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.