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.
Our guide for a new flat roof in the South East comes to £2,200–£5,000 with VAT added, and that range applies across Kent, including Maidstone, Gillingham, Chatham and Tunbridge Wells. Your own price depends on the size of the job, the specification and how easy it is to work on the site. We survey for free, check any consents needed under the rules in England, and then put the price in writing.
- Guide price
- £2,200–£5,000 inc VAT
- Time on site
- 1–3 days for most roofs
- Planning rules
- England
- Price level
- About 12% above the national guide
- Towns listed
- 23
- Survey
- Free, with a written quote
How much does a new flat roof cost in Kent?
Budgeting for a new flat roof in Kent? The numbers below include VAT and are adjusted for the South East, where costs are about 12% above the national guide. The headline range is £2,200–£5,000. Nothing is final until we have measured up at a free survey and agreed the specification with you.
| Type of job | What it usually involves | Guide in Kent |
|---|---|---|
| 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 |
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
- 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
- Rooflights refitted or replaced where required
Homes in Kent
Kent's older buildings include oast houses, weatherboarded cottages, Wealden timber-framed houses and Kentish ragstone walls. Medway towns have long rows of Victorian terraces, Margate and Ramsgate have Regency and Victorian seafronts, and Ashford, Maidstone and Dartford have seen large new estates alongside interwar and post-war housing.
Victorian terraces suit loft rooms and rear extensions; weatherboarded and timber-framed buildings may need cladding repairs and lime work. Newer estate homes often take garage conversions, porches and landscaping.
One of England's sunnier, drier counties, but Thanet and the coast are windy, and Weald and London Clay soils can shrink in summer.
Planning and building rules in Kent
For anyone in Kent, the relevant framework is England's. The summary below is general, so we always contact the council about your address before putting a price in writing.
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
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.
Written quote
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
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.
Build and hand over
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
How we work
Frequently asked questions
Can you combine a new flat roof with other work?
Yes. Because we manage several trades under one contract, we can plan a new flat roof alongside other work on your Kent home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
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.
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.
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.
Towns in Kent
Choose your town from the list to see how we price and plan a new flat roof in your part of Kent, including typical time on site.