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.
For a homeowner in Sunbury-on-Thames, planning a new flat roof tends to begin with two questions: what will it cost, and how disruptive will it be? Our guide range is £2,200–£5,000 including VAT, and a typical job runs to 1–3 days for most roofs. Both numbers firm up once we have seen the property, measured up and agreed exactly what is included.
- Guide price
- £2,200–£5,000 inc VAT
- Time on site
- 1–3 days for most roofs
- Postcodes
- KT8, KT12, TW12, TW15 and TW16
- Planning rules
- England
- Local area
- Surrey
- Survey
- Free, with a written quote
How much does a new flat roof cost in Sunbury-on-Thames?
What should you budget for a new flat roof in Sunbury-on-Thames? Use the figures below as a starting point. Prices in the South East sit about 12% above the national guide, so the range here is £2,200–£5,000 including VAT. Your fixed price comes in writing once we've surveyed the property, at no charge.
| Type of job | What it usually involves | Guide in Sunbury-on-Thames |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £900–£2,200 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £2,200–£5,000 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £4,500–£10,000 |
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
What’s included?
- Survey of the covering, deck, falls, upstands and drainage
- Stripping and disposal of the old roof covering
- 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
- New trims, outlets and gutter connections
Local housing and a new flat roof
Surrey has many Victorian and Edwardian villas, interwar semis in the commuter towns near London, and Arts and Crafts houses with tile-hanging and tall chimneys. Bargate stone appears around Godalming, and large detached homes are common in Guildford, Woking, Weybridge and the Surrey Hills villages.
Larger homes often take kitchen extensions, bifold doors, landscaping and driveway renewal. Interwar semis suit loft and side extensions, while tile-hung and period properties may need roof and hanging-tile repairs.
For a new flat roof in Sunbury-on-Thames, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Do you need permission in Sunbury-on-Thames?
As Sunbury-on-Thames is in England, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a 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.
What happens after you get in touch?
We look at the job
A free survey comes first. It gives us what we need to price a new flat roof properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Your fixed price
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a new flat roof.
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.
On site to finish
Our trades complete a new flat roof while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
Why homeowners choose us
Flat roofs in Sunbury-on-Thames: 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.
Can you repair my flat roof instead of replacing it?
A flat roof can often be repaired if the damage is limited to a small split, a failed joint or a loose upstand and the rest of the covering is sound. If the deck is soft, the covering is blistered or cracked across the roof, or leaks keep returning, replacement is usually better value. We assess the whole roof and give you an honest recommendation.
Do I need planning permission in Sunbury-on-Thames?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Sunbury-on-Thames is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
Is a flat roof suitable for a roof terrace?
A flat roof can only be used as a terrace if it is designed for it, with joists strong enough for people and furniture, a hard-wearing surface, safe edge protection and correct drainage. Using a standard extension roof as a terrace can damage it and may need planning permission and building regulations approval. We can advise on what a conversion would involve.
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.
Nearby towns
Whether you're in the centre of Sunbury-on-Thames or on its outskirts, KT8, KT12, TW12 and TW15 addresses are covered. We extend the same service, and the same fixed-price approach, to Walton-on-Thames, West Molesey and Hampton.