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.
We offer a new flat roof throughout Cornwall, from Redruth, Falmouth, St Austell and Truro to the smaller places in between. Each project starts with a free survey at your home and ends with a written figure, fixed for the work you choose. Because Cornwall is in England, we work to the planning system and building standards used there, and guide prices for the South West run at £2,000–£4,600 including VAT.
- Guide price
- £2,000–£4,600 inc VAT
- Time on site
- 1–3 days for most roofs
- Planning rules
- England
- Price level
- About 2% above the national guide
- Towns listed
- 7
- Survey
- Free, with a written quote
Flat roofs prices in Cornwall
To help you plan, we show what a new flat roof typically costs in Cornwall instead of holding figures back for a sales call. The range is £2,000–£4,600 with VAT, using rates in the South West that are about 2% above the national guide. A free survey then fixes your actual price.
| Type of job | What it usually involves | Guide in Cornwall |
|---|---|---|
| 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 |
What moves the price up or down:
- Roof area and access to the roof
- Condition of the deck and joists underneath
- Insulation upgrades and changes to roof height at edges
- Number of rooflights, pipes and upstands to detail
What’s included?
- Survey of the covering, deck, falls, upstands and drainage
- Stripping and disposal of the old roof covering
- New EPDM, GRP or torch-on felt membrane laid to falls
- Upstands, flashings and drip edges finished neatly
- New trims, outlets and gutter connections
- Rooflights refitted or replaced where required
Housing across Cornwall
Older Cornish homes are often built of granite or slatey local stone, with slate roofs and sometimes slate-hung walls facing the weather. Cob cottages survive in places, Truro and Falmouth keep Georgian and Victorian streets, and many towns have rendered post-war houses, bungalows and newer estates on their edges.
Stone and cob properties often need breathable lime render, careful repointing and roof repairs. Post-war and newer homes commonly benefit from new windows, roofline renewal, external rendering and single-storey extensions.
Cornwall faces Atlantic gales, driving rain and salt-laden air, so render, pointing and window hardware on exposed elevations need a suitably robust specification.
Planning and building rules in Cornwall
Cornwall 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.
The four stages
We look at the job
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.
Your fixed price
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.
Dates and permissions
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a new flat roof are in place before the first day on site.
On site to finish
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
What you can expect from us
Questions about a new flat roof in Cornwall
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.
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a new flat roof, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
Which postcodes in Cornwall do you cover?
We cover TR15, TR11, PL25 and TR1, along with the rest of Cornwall. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
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.
Towns in Cornwall
Looking for a new flat roof somewhere in Cornwall? Start with the towns below; each links to a page with pricing for your region and coverage details.