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.
Homes across Wiltshire vary a great deal, so we price a new flat roof only after seeing the property. Our coverage takes in Swindon, Salisbury, Trowbridge and Chippenham and the surrounding districts. As a guide, expect £2,000–£4,600 including VAT in the South West; the final figure depends on size, materials and access. Any permissions are checked against the rules for England before we quote.
- 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
- 5
- Survey
- Free, with a written quote
How much does a new flat roof cost in Wiltshire?
What will a new flat roof cost in Wiltshire? Our guide range is £2,000–£4,600 including VAT. That figure is adjusted for the South West, about 2% above the national guide, and is intended for planning a budget. A firm written price for your chosen specification follows a free survey at your home.
| Type of job | What it usually involves | Guide in Wiltshire |
|---|---|---|
| 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:
- 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 do you get?
- Survey of the covering, deck, falls, upstands and drainage
- 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
Housing across Wiltshire
Salisbury has medieval and Georgian streets, the north-west around Corsham and Bradford on Avon uses Bath stone, and chalk and flint appear on the downland. Swindon has railway-village terraces and very large post-war and modern estates, and many Wiltshire villages have thatched cottages, some with chalk cob walls.
Cob and Bath stone walls need breathable, lime-based repairs, and thatched cottages may need careful roof work. Swindon's railway terraces suit loft rooms and rear extensions, while its large estates often add garage conversions, driveways and landscaping.
Salisbury Plain and the downs are exposed to wind and frost, while river valleys around Salisbury and the Avon can flood.
Do you need permission in Wiltshire?
Wiltshire 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?
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.
Price and scope agreed
After the survey we send a quote for a new flat roof that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Booking the work
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.
The work itself
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.
How we work
Frequently asked questions
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.
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 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.
Do you cover Swindon, Salisbury and Trowbridge?
Yes. As well as Wiltshire, we cover Swindon, Salisbury and Trowbridge and the rest of Wiltshire. 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.
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.
Towns in Wiltshire
These are the towns in Wiltshire where you can book a free survey for a new flat roof. Each has its own page with guide prices and coverage details.