Dewsbury at a glance
- Postcode districts
- BD11, BD19, WF12, WF13, WF15, WF16, WF17
- Population
- about 61,035 (GeoNames)
- Council area
- Kirklees Council
- Building approval
- Kirklees Council building control, or a registered building control approver
- Nearest main town
- Wakefield, about 5 miles
- Guide price region
- Yorkshire and the Humber (−5% on West Midlands rates)
What makes a good extension roof in Dewsbury?
Extension roofs in Dewsbury are often replaced because the original was built cheaply: thin chipboard decks, little or no insulation and felt turned up the wall without a proper flashing. Twenty or thirty years on, those weaknesses show up as leaks at the back wall and a cold, damp ceiling.
In and around Dewsbury, flat roofs are typically found on terraced streets with flat-roofed rear kitchens and bathrooms, and on low-rise post-war blocks of flats. England averages roughly 870 mm of rain a year; the Pennine side of Yorkshire is wetter and windier than the east, so we specify for the site rather than the county.
How much does a new extension roof cost in Dewsbury?
Guide price in Dewsbury: £2,650–£4,650 for a 20 m² extension roof in EPDM with a new deck and insulation, including VAT at Yorkshire and the Humber 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 | £2,650–£4,650 |
| Extension (20 m²), GRP, new deck + insulation | £2,850–£5,100 |
| Extension (20 m²), EPDM, insulation + 1 rooflight upstand | £2,850–£4,950 |
| Single garage (18 m²), EPDM rubber | £1,500–£2,650 |
Why does water pond or leak where the extension meets the house?
Usually because the fall runs the wrong way, the abutment detail has failed, or the roof has sagged close to the wall. The junction with the house is the most common leak point on an extension roof.
If the roof falls towards the house, or the deck dips near the wall, water sits against the upstand and finds any weakness in the flashing above. Older roofs often have the felt simply turned up the brickwork with no cover flashing, or a flashing that has pulled out of its joint. A patch will not change a fall. We re-firr or use tapered insulation so water runs away from the wall, then form a new upstand, usually 150 mm above the finished roof, with a flashing chased into the mortar joint.
Rooflights and lanterns are the other weak point. A lantern needs a properly built kerb with the membrane dressed up and under its frame. We rebuild rooflight upstands within the roof job; we do not supply the lantern itself. Our guide to ponding water explains the causes in more depth.
What's included?
- Staged strip-out so the room stays weathertight
- Building control handled where needed, and a written workmanship guarantee
- New deck, vapour control layer and warm-roof insulation
- Falls set away from the house wall
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?
Extension and kitchen roofs in Dewsbury: questions
Do you cover Dewsbury?
Yes. Dewsbury is part of our West Yorkshire coverage, including postcode districts BD11, BD19, WF12, WF13, WF15, WF16 and 1 more. 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 Dewsbury?
Where the work needs approval it goes to Kirklees 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 new extension roof cost in Dewsbury?
£2,650–£4,650 for a 20 m² extension roof in EPDM with a new deck and insulation, at Yorkshire and the Humber guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Why does my extension ceiling get damp in winter if the roof isn't leaking?
That is often condensation in a cold roof, where warm, moist air reaches the cold underside of the deck. A warm-roof replacement with a vapour control layer usually solves it.
Do I need my neighbour's permission to replace an extension roof?
Not for a like-for-like re-cover in most cases. The Party Wall Act in England and Wales can apply if the work raises or cuts into a shared wall, so we flag that at survey.