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.
Anyone planning a new flat roof in Chorley wants three things: a clear price, a realistic timetable and a tidy job. We publish a guide of £1,900–£4,300 including VAT for the North West up front, explain that work normally takes 1–3 days for most roofs, and confirm both in writing after a free survey of your property.
- Guide price
- £1,900–£4,300 inc VAT
- Time on site
- 1–3 days for most roofs
- Postcodes
- PR6 and PR7
- Planning rules
- England
- Local area
- Lancashire
- Survey
- Free, with a written quote
Flat roofs prices in Chorley
In Chorley, guide figures for a new flat roof sit at £1,900–£4,300, VAT included. We set them using rates for the North West, currently about 5% below the national guide. The table shows what pushes a project towards either end of the range; your own price is set after a free survey.
| Type of job | What it usually involves | Guide in Chorley |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £750–£1,900 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £1,900–£4,300 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £3,800–£8,600 |
Expect these to shape the final quote:
- Covering system: EPDM, GRP or torch-on felt
- 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?
- Stripping and disposal of the old roof covering
- Replacement of rotten or soft deck boards
- 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
Local housing and a new flat roof
East Lancashire mill towns such as Burnley, Blackburn and Accrington have long rows of stone and brick terraces, while Preston is mostly red brick. Lancaster uses sandstone for its Georgian centre, Blackpool and the Fylde coast have guest-house terraces and many bungalows, and interwar and newer estates surround most towns.
Westerly winds and high rainfall are the norm, with gales on the Fylde coast and wetter, colder conditions on the Pennine side.
Knowing the typical building types in Lancashire helps, but a survey of your own home in Chorley is what decides the right approach to a new flat roof.
Planning and building rules in Chorley
Each UK nation sets its own consent rules, and Chorley is in England. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
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
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.
Price and scope agreed
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.
Getting ready
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.
Why homeowners choose us
Common questions
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 much will a new flat roof cost in Chorley?
As a guide, expect to pay £1,900–£4,300 including VAT for a new flat roof in Chorley. That range is adjusted for the North West, which runs about 5% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
How much does a new flat roof cost?
Re-covering a typical 15–25m² extension or garage roof costs £1,900–£4,300. 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.
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.
Do you cover Horwich, Leyland and Darwen?
Yes. As well as Chorley, we cover Horwich, Leyland and Darwen and the rest of Lancashire. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Also covering areas around Chorley
Live in Chorley? Our coverage takes in the PR6 and PR7 postcode areas and reaches out to Horwich, Leyland and Darwen, so homes on the outskirts and in the next town along are included.

