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.
If you live in St Austell and are weighing up a new flat roof, the starting point is a visit to measure up and talk through what you want, which costs nothing. We cover homes across PL25, and a typical project of this kind in the South West lands somewhere in the £2,000–£4,600 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £2,000–£4,600 inc VAT
- Time on site
- 1–3 days for most roofs
- Postcodes
- PL25
- Planning rules
- England
- Local area
- Cornwall
- Survey
- Free, with a written quote
How much does a new flat roof cost in St Austell?
Below is a breakdown of typical costs for a new flat roof in St Austell. Because rates in the South West are about 2% above the national guide, the overall guide comes to £2,000–£4,600, including VAT. Size, materials and access move the figure, and a free-of-charge survey settles it.
| Type of job | What it usually involves | Guide in St Austell |
|---|---|---|
| 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
- Covering system: EPDM, GRP or torch-on felt
- Condition of the deck and joists underneath
- Insulation upgrades and changes to roof height at edges
What’s included?
- Survey of the covering, deck, falls, upstands and drainage
- 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
- New EPDM, GRP or torch-on felt membrane laid to falls
- Upstands, flashings and drip edges finished neatly
What are homes like around St Austell?
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.
Cornwall faces Atlantic gales, driving rain and salt-laden air, so render, pointing and window hardware on exposed elevations need a suitably robust specification.
That mix of housing shapes how we approach a new flat roof in St Austell: the age and construction of your home affect the materials, the method and, in the end, the price.
Planning and building rules in St Austell
Because St Austell falls under England's rules, the guidance below is the version relevant to you. Before sending a price, we check your property's position with the council.
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
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a new flat roof.
Quote in writing
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Dates and permissions
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
Build and hand over
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
How we work
Questions about a new flat roof in St Austell
Should I insulate my flat roof when it is replaced?
Replacing a flat roof is the most cost-effective time to add insulation, because the covering is already off. A warm roof, with insulation laid above the deck, keeps the structure warm and reduces condensation risk. Building regulations may require insulation when a large part of the roof is renewed. It raises the roof height slightly, which affects trims and upstands.
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.
Why does water sit on my flat roof?
Ponding water on a flat roof is usually caused by inadequate falls, sagging joists, a deck that has dipped or blocked outlets. Small puddles that dry within a day or two are not always a problem, but standing water speeds up wear and finds any weakness. A new roof can be laid on firring strips or tapered insulation to create proper falls. We check falls during the survey.
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.
How much does a new flat roof cost?
Re-covering a typical 15–25m² extension or garage roof costs £2,000–£4,600. As a guide, allow around £75–£170 per square metre plus fixed costs for stripping, waste and access, with torch-on felt at the lower end and GRP or EPDM with new decking or insulation at the top. Small dormer and porch roofs cost less overall but more per square metre. We confirm a fixed price after the survey.
Also covering areas around St Austell
Whether you're in the centre of St Austell or on its outskirts, PL25 addresses are covered. We extend the same service, and the same fixed-price approach, to Truro, Newquay and Falmouth.