Harrow at a glance
- Postcode districts
- HA3, HA1, HA2, HA7, HA5, HA8, HA6
- Council area
- London Borough of Harrow
- Building approval
- London Borough of Harrow building control, or a registered building control approver
- Guide price region
- London (+20% on West Midlands rates)
Why choose single-ply roofing in Harrow?
On exposed sites in Harrow and elsewhere, mechanically fixed single-ply is specified with a fixing pattern based on wind uplift, with extra fasteners at corners and edges. That makes it a strong option for commercial roofs where wind loads are a concern.
In and around Harrow, flat roofs are typically found on mansard and dormer loft conversions, and on shops with flat-roofed stores below flats above. 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 Harrow?
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 |
Should a single-ply roof be mechanically fixed or adhered, and how are the seams welded?
Most commercial single-ply roofs are mechanically fixed, while adhered systems suit decks that cannot take fixings or roofs where a smooth finish is wanted. The choice depends on the deck, the wind exposure of the site and the manufacturer's specification.
| Method | How it works | Typical use |
|---|---|---|
| Mechanically fixed | Fasteners and plates hold the membrane through the insulation into the deck, hidden under the lap of the next sheet | Metal, timber and concrete decks on commercial roofs |
| Adhered | Membrane bonded to the insulation or deck with adhesive | Domestic roofs, roofs where fixings are unsuitable |
| Ballasted | Loose-laid and held down by paving, gravel or a green roof | Inverted roofs, terraces, green roofs |
Fixing patterns are worked out for the site, with more fasteners at corners and perimeters, where wind uplift is strongest.
Seams are welded by hot-air machines and hand tools that melt the overlapping edges so they fuse. Each seam is then probed along its length to find any gaps, and test welds are made at the start of the day to set the machine for the weather. On commercial jobs we also check that walkways protect the membrane around plant.
What's included?
- Hot-air welded seams, each probed along its full length
- PVC, TPO or FPO membrane, mechanically fixed, adhered or ballasted
- Edge protection on every job and walkway protection around plant
- Vapour control layer and warm-roof or tapered insulation as specified
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?
Single-ply membrane roofing in Harrow: questions
Do you cover Harrow?
Yes. Harrow is part of our London coverage, including postcode districts HA3, HA1, HA2, HA7, HA5, HA8 and 1 more. 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 Harrow?
Where the work needs approval it goes to London Borough of Harrow 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 Harrow?
£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.
Can single-ply roofing be laid over an existing roof?
Sometimes, if the existing roof and deck are dry and sound, often with a separation layer or new insulation on top. Wet insulation or a damaged deck means stripping first.
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.