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 torch-on felt roofing in Harrow?
Torch-on felt is widely specified for blocks of flats and HMOs, in Harrow as elsewhere, because the system is well understood, widely repairable and governed by a British Standard code of practice. Three-layer builds with insulation are common on larger, multi-occupied roofs.
Harrow's flat roofs are mostly on Victorian and Edwardian terraces with flat-roofed back additions, 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 torch-on felt roof cost in Harrow?
For Harrow we use London rates: £1,800–£3,150 is the guide for a typical 18 m² garage roof in torch-on felt, VAT included. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Single garage (18 m²), torch-on felt | £1,800–£3,150 |
| Extension (20 m²), felt, new deck + insulation | £3,250–£5,600 |
| Block of flats (150 m²), felt + insulation + scaffold | £18,650–£32,650 |
| Single garage (18 m²), EPDM rubber | £1,900–£3,350 |
| Extension (20 m²), EPDM, new deck + insulation | £3,350–£5,850 |
How long does a torch-on felt roof last, and what is the guarantee?
A modern torch-on roof typically lasts 15 to 25 years, and high-performance systems with better membranes can last longer. That is a big step up from older felt roofs, which were often single-layer, unreinforced or poorly bonded.
What shortens the life of a felt roof is usually visible: mineral chippings worn away so the bitumen is exposed to sunlight, blisters where moisture was trapped, split laps, and upstands that have slumped or pulled away from the wall. Ponding speeds all of this up.
Manufacturer material guarantees are available on many specified torch-on systems; they often depend on a particular build-up and registration, which we handle where the system allows. Every re-roof also comes with our written workmanship guarantee, the length of which is stated in the quote, and insurance-backed options can be discussed. Our flat roof lifespan guide compares felt with the other systems.
What's included?
- Deck inspection with replacement of damaged boards
- Vapour control layer and warm-roof insulation where needed
- Two- or three-layer reinforced bitumen membrane with staggered laps
- Strip-off of the existing roof covering and removal of waste
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?
Torch-on felt 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 torch-on felt roof cost in Harrow?
£1,800–£3,150 for a typical 18 m² garage roof in torch-on felt, at London guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Is torch-on felt better than the old felt roofs?
Yes, considerably. Modern torch-on membranes are polymer-modified and polyester-reinforced, laid in bonded layers, and typically last much longer than the older felt systems they replace.
How long does it take to lay a torch-on felt roof?
A garage roof typically takes one to two days and an insulated extension two to three. Larger roofs and blocks are phased over longer, with each area made weathertight before the team leaves.