Portishead at a glance
- Postcode districts
- BS20
- Population
- about 26,355 (GeoNames)
- Council area
- North Somerset Council
- Building approval
- North Somerset Council building control, or a registered building control approver
- Nearest main town
- Bristol, about 8 miles
- Guide price region
- South West (+3% on West Midlands rates)
When should a flat roof in Portishead be replaced?
A sensible moment to replace a flat roof in Portishead 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.
In and around Portishead, flat roofs are typically found on bungalows with flat-roofed side extensions and dormers, and on terraced streets with flat-roofed rear kitchens and bathrooms. 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 Portishead?
Guide price in Portishead: £2,900–£5,050 for a 20 m² extension roof in EPDM with a new deck and insulation, including VAT at South West 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 | £2,900–£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 |
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.
What's included?
- New deck, firrings and warm-roof insulation where needed
- Building control handled where needed, plus a written workmanship guarantee
- Free survey of the deck, falls, edges and insulation
- New membrane, upstands, edge trims and outlets
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 Portishead: questions
Do you cover Portishead?
Yes. Portishead is part of our Somerset coverage, including postcode districts BS20. 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 Portishead?
Where the work needs approval it goes to North Somerset 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 Portishead?
£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.
Do I need to be at home while the roof is replaced?
Not for most of the job, as long as the team can reach the roof and there is room for a skip. We ask you to be there at the start to agree the plan and at the end to look over the finished roof.
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.