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)
Why choose single-ply roofing in Merton?
Single-ply often suits blocks and mixed-use buildings in Merton because no flame is used on the roof, which can make work around residents and businesses easier to plan. Hot-air welding still needs care, but the fire risk is lower than with torch-on.
Merton's flat roofs are mostly on shops with flat-roofed stores below flats above, with plenty on kitchen extensions and roof terraces behind period houses too. 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 single-ply roof cost in Merton?
At London guide rates, a 100 m² commercial roof in single-ply with insulation comes to £15,900–£26,150 including VAT. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Commercial roof (100 m²), single-ply + insulation | £15,900–£26,150 |
| Single garage (18 m²), single-ply | £2,450–£4,000 |
| Single garage (18 m²), EPDM rubber | £1,900–£3,350 |
| Extension (20 m²), EPDM, new deck + insulation | £3,350–£5,850 |
What insulation and approvals does a single-ply re-roof need?
On a heated building, a full single-ply re-roof usually triggers the thermal-element rules, so insulation should be brought towards the renovation standard where feasible. In England that is 0.18 W/m²K for non-domestic and 0.16 W/m²K for domestic roofs, with Wales and Northern Ireland setting their own figures; Scottish roofs follow Section 6 of the building standards, and the council confirms whether a building warrant is required.
Single-ply suits a warm roof well, and tapered insulation can correct poor falls at the same time. A thicker build-up raises the roof, so we check upstand heights, door thresholds and rooflight kerbs at survey. Near boundaries, the external fire classification of the tested build-up can matter. We handle building control or building standards where needed; see the building regulations page.
What's included?
- Hot-air welded seams, each probed along its full length
- Strip-out or preparation of the existing roof, with waste removed
- Vapour control layer and warm-roof or tapered insulation as specified
- Welded details at upstands, outlets, rooflight kerbs and edge trims
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
Single-ply membrane roofing 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 single-ply roof cost in Merton?
£15,900–£26,150 for a 100 m² commercial roof in single-ply with insulation, at London guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
What is the difference between PVC and TPO roofing?
Both are thermoplastic single-ply membranes welded with hot air. PVC contains plasticisers and usually needs separating from bitumen, while TPO and FPO are polyolefin-based; the right one depends on the roof and the system specified.
Does single-ply work with solar panels or a green roof?
Usually, yes. Many systems can be specified for sedum or ballasted green roofs, and solar mounts can be welded or ballasted, though the structure and wind loads must be checked first.