Merton at a glance
- Postcode districts
- SM4, SW20, SW19, CR4
- Council area
- London Borough of Merton
- Building approval
- London Borough of Merton building control, or a registered building control approver
- Guide price region
- London (+20% on West Midlands rates)
When does a garage roof in Merton need replacing?
A garage in Merton that is becoming a workshop, gym or home office is a good reason to replace its roof. That is the moment to think about insulation and a warm-roof build-up, so the roof does not have to be stripped again when the space is heated.
In and around Merton, flat roofs are typically found on kitchen extensions and roof terraces behind period houses, and on Victorian and Edwardian terraces with flat-roofed back additions. The Thames basin is one of the drier parts of Britain at roughly 730 mm of rain a year, but summer heat is the bigger test here: dark membranes on south-facing roofs swing a long way in temperature.
How much does a new garage roof cost in Merton?
At London guide rates, a typical 18 m² garage roof in EPDM comes to £1,900–£3,350 including VAT. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Single garage (18 m²), EPDM rubber | £1,900–£3,350 |
| Single garage (18 m²), torch-on felt | £1,800–£3,150 |
| Single garage (18 m²), GRP fibreglass | £2,150–£3,900 |
| Extension (20 m²), GRP, new deck + insulation | £3,600–£6,450 |
What if my garage roof is asbestos cement or old felt?
If your garage has corrugated cement sheets, especially on a pre-2000 building, assume they could contain asbestos until a test says otherwise. We do not remove asbestos; any suspected material is tested and, if confirmed, removed by a licensed specialist before our work starts.
Once the old sheets have gone, the garage usually needs new timber joists or purlins and a deck before a membrane can go on. Old felt garages are more straightforward: the felt is stripped and the deck assessed in the usual way.
Lock-up blocks and rows of garages bring their own issues. A shared roof often has several owners, so we can quote per bay, or for the whole run where everyone agrees, which keeps the edges and joins between garages consistent. Attached garages need careful upstands and flashings where the roof meets the house wall, while detached ones are about edges, gutters and falls.
Not sure whether your roof needs replacing? Our guide to repair or replace sets out the signs.
What's included?
- Gutter or outlet renewed where the old one has failed
- Written workmanship guarantee, with material guarantees registered where available
- Replacement of soft or swollen deck boards
- Free survey of the deck, fall and gutter line
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
- Sutton · 3 mi
- Wandsworth · 4 mi
- Kingston upon Thames · 5 mi
- Croydon · 5 mi
- Lambeth · 5 mi
- Richmond upon Thames · 6 mi
Garage roofs in Merton: questions
Do you cover Merton?
Yes. Merton is part of our London coverage, including postcode districts SM4, SW20, SW19, CR4. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Merton?
Where the work needs approval it goes to London Borough of Merton building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a new garage roof cost in Merton?
£1,900–£3,350 for a typical 18 m² garage roof in EPDM, at London guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Is it worth repairing a garage roof instead?
If the roof is generally sound and dry with one isolated defect, a repair is usually sensible. Widespread cracking, a soft deck or repeat leaks point to replacement.
How long does a garage roof last?
It depends on the system. As indicative figures, EPDM lasts 25–50 years, GRP 20–40 and modern torch-on felt 15–25, with good specification and maintenance.