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Flat roof systems

Torch-on felt roofing in Westminster

Replacing an old felt roof in Westminster? Modern torch-on systems are far tougher than the felt many people remember. We strip the existing covering, repair the deck, add warm-roof insulation where needed and lay new membranes with staggered laps. Guide prices are online, and the fixed price comes after our free survey.

Roofer torching a slate-grey mineral cap sheet on a commercial flat roof behind edge protectionComputer-generated example image

Westminster at a glance

Postcode districts
W1K, W1C, W1H, W1U, W1M, W1G, W1, W1J and 20 more
Council area
City of Westminster
Building approval
City of Westminster building control, or a registered building control approver
Guide price region
London (+20% on West Midlands rates)

Why choose torch-on felt roofing in Westminster?

On larger roofs in Westminster with poor falls, torch-on felt pairs well with tapered insulation, which builds the fall into the insulation boards. That deals with ponding properly while adding insulation, rather than patching the low spots and waiting for the next leak.

In a town like Westminster, flat roofs are commonly found on kitchen extensions and roof terraces behind period houses or mansion blocks and purpose-built flats with large flat roofs. 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 Westminster?

Guide price in Westminster: £1,800–£3,150 for a typical 18 m² garage roof in torch-on felt, including VAT at London rates. The fixed price comes after a free survey for new and replacement roofs.

JobGuide 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?

  • Vapour control layer and warm-roof insulation where needed
  • Two- or three-layer reinforced bitumen membrane with staggered laps
  • Hot-works checks and fire watch on every torch-on job
  • Mineral-finished cap sheet, upstands, outlets 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?

Torch-on felt roofing in Westminster: questions

Do you cover Westminster?

Yes. Westminster is part of our London coverage, including postcode districts W1K, W1C, W1H, W1U, W1M, W1G and 22 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 Westminster?

Where the work needs approval it goes to City of Westminster 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 Westminster?

£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.

Can torch-on felt be laid in wet weather?

Not in rain or on a wet deck, because moisture trapped under the membrane causes blisters. Light cold weather is usually workable, but we will postpone rather than lay on a damp surface.

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.

Other flat roof work in Westminster

Torch-on felt roofing in Westminster: get a fixed price

Free survey and a written fixed quote for replacement and new roofs. No obligation.

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