A flat roof replacement strips the old covering from a low-pitched roof and lays a new waterproof system, usually EPDM rubber, GRP fibreglass or torch-on felt, over a sound deck with correct falls, upstands, trims and outlets so rainwater drains away.
Getting a new flat roof right in Keynsham starts with understanding the house you already have: its age, how it was built and what has been altered over the years. We survey first, then commit on paper to a price that holds as long as the scope stays the same. Across the South West, guide prices run at £2,000–£4,600 including VAT, and homes in Kingswood, Mangotsfield and Bishopsworth are covered too.
- Guide price
- £2,000–£4,600 inc VAT
- Time on site
- 1–3 days for most roofs
- Postcodes
- BS31
- Planning rules
- England
- Local area
- Bath and North East Somerset
- Survey
- Free, with a written quote
What should you budget for a new flat roof in Keynsham?
The table below shows guide prices for a new flat roof in Keynsham. They are based on rates in the South West, which run about 2% above the national guide, giving an overall range of £2,000–£4,600. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in Keynsham |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £800–£2,000 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £2,000–£4,600 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £4,100–£9,200 |
Your price depends mostly on:
- Roof area and access to the roof
- Covering system: EPDM, GRP or torch-on felt
- Condition of the deck and joists underneath
- Insulation upgrades and changes to roof height at edges
Scope of the work
- Stripping and disposal of the old roof covering
- Replacement of rotten or soft deck boards
- Insulation upgrade to a warm roof build-up where agreed
- Upstands, flashings and drip edges finished neatly
- New trims, outlets and gutter connections
- Rooflights refitted or replaced where required
Homes in Somerset
Somerset's building stone varies widely: Bath stone in Bath, golden Ham stone around Yeovil, blue lias in villages on the Levels and Mendip stone in the north. Weston-super-Mare has Victorian villas and terraces, Taunton and Bridgwater have brick terraces and post-war estates, and new housing continues to spread around the larger towns.
Stone properties often need lime pointing, stone repairs and windows that respect conservation areas, especially in Bath. Brick terraces suit loft rooms and extensions, and estate homes commonly take garage conversions.
That variety is why a guide price for a new flat roof in Keynsham is only a starting point; the survey shows what your particular property needs.
Do you need permission in Keynsham?
Keynsham is in England, so the planning and building rules set out below are the ones that apply. We confirm the details with the council before we quote.
Re-roofing a house with similar materials does not usually need planning permission in England. Listed buildings and conservation areas may need consent if the covering changes.
Replacing more than a quarter of a roof’s covering counts as renovation under Building Regulations, so the work is notified and the roof insulation may need upgrading. Bats are protected across the UK; if they roost under roof tiles, soffits or fascias, work stops and a licensed ecologist advises before it restarts.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Survey and measure
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a new flat roof so the price reflects your home.
Quote in writing
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Booking the work
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
Build and hand over
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
Why homeowners choose us
Frequently asked questions
Is the price fixed?
Yes, for the specification we agree. Your written quote sets out exactly what is included at a fixed price. It only changes if you ask for something different, or if a problem the survey could not reasonably reveal later needs extra work. In either case we explain the change and confirm it in writing before going ahead.
Which is better, EPDM rubber or GRP fibreglass?
EPDM rubber and GRP fibreglass are both reliable modern flat roof systems. EPDM is a single flexible sheet with very few joints, which copes well with movement and suits most extensions and garages. GRP is a hard, seamless finish that copes better with foot traffic and complex shapes, but needs dry weather to apply. Felt costs less but usually lasts less long. We recommend a system after seeing your roof.
How long does a flat roof last?
A well-installed EPDM or GRP flat roof can last 25 years or more, while torch-on felt systems typically last around 15–25 years, depending on quality and exposure. Lifespan depends on correct falls, good detailing at edges and upstands, and keeping outlets clear. Foot traffic, ponding and poor ventilation shorten it. Annual checks help catch small problems early.
How long does a flat roof replacement take?
Replacing a typical extension or garage flat roof usually takes one to three days. Stripping and any deck repairs come first, then insulation where agreed, the new membrane and the trims and outlets. GRP needs dry weather and time to cure, and we plan around the forecast. Larger roofs or roofs with many rooflights take longer. We confirm timing with your quote.
How long will a new flat roof take?
On a typical home, allow 1–3 days for most roofs. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
Nearby towns
Whether you're in the centre of Keynsham or on its outskirts, BS31 addresses are covered. We extend the same service, and the same fixed-price approach, to Kingswood, Mangotsfield and Bishopsworth.