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Flat roof systems

Torch-on felt roofing in Windsor

Replacing an old felt roof in Windsor? 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

Windsor at a glance

Postcode districts
SL4
Population
about 31,560 (GeoNames)
Council area
Royal Borough of Windsor and Maidenhead
Building approval
Royal Borough of Windsor and Maidenhead building control, or a registered building control approver
Nearest main town
Slough, about 2 miles
Guide price region
South East (+10% on West Midlands rates)

Why choose torch-on felt roofing in Windsor?

Torch-on felt suits property owners in Windsor who want a dependable, layered roof without paying the top price per square metre. With two or three bonded layers, a single small defect in one sheet need not lead to a leak, which is a real advantage on larger roofs that are hard to inspect often.

In a town like Windsor, flat roofs are commonly found on terraced streets with flat-roofed rear kitchens and bathrooms or lock-up garage blocks on estates. Much of the South East sits in the drier Thames catchment at roughly 730 mm of rain a year, so the usual failures are at joints, upstands and outlets rather than from sheer volume of rain.

How much does a torch-on felt roof cost in Windsor?

For Windsor we use South East rates: £1,650–£2,900 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.

JobGuide price inc VAT
Single garage (18 m²), torch-on felt£1,650–£2,900
Extension (20 m²), felt, new deck + insulation£3,000–£5,150
Block of flats (150 m²), felt + insulation + scaffold£17,100–£29,900
Single garage (18 m²), EPDM rubber£1,750–£3,100
Extension (20 m²), EPDM, new deck + insulation£3,100–£5,350

Is torch-on roofing safe, and what is the difference between two- and three-layer systems?

Yes, torch-on is safe when hot works are properly controlled, because most roof fires linked to torching start at hidden timber or debris near edges and upstands, not on the open roof. Our teams follow a hot-works routine on every job:

  • check eaves, fascias, soffits and wall cavities for timber, nests and debris before lighting a torch;
  • use a cold-applied or self-adhesive membrane, rather than a flame, at edges, against combustible materials and in tight details;
  • keep fire extinguishers on the roof and the gas bottles secured and away from the work;
  • stop torching well before the team leaves, then carry out a fire watch so smouldering is spotted while people are still on site.

As for layers, a two-layer system (underlay plus cap sheet) is common on domestic roofs such as garages and extensions. A three-layer system adds an intermediate sheet, giving more thickness and redundancy, and is often specified on larger, commercial and multi-occupied roofs. The right choice depends on the size and use of the roof and the system's requirements, so we set it out in the quote.

Near a boundary, the external fire performance of the tested build-up, such as a BROOF(t4) classification, can also matter, and we check it where it applies.

What's included?

  • Vapour control layer and warm-roof insulation where needed
  • Deck inspection with replacement of damaged boards
  • Two- or three-layer reinforced bitumen membrane with staggered laps
  • Hot-works checks and fire watch on every torch-on job

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 Windsor: questions

Do you cover Windsor?

Yes. Windsor is part of our Berkshire coverage, including postcode districts SL4. 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 Windsor?

Where the work needs approval it goes to Royal Borough of Windsor and Maidenhead 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 Windsor?

£1,650–£2,900 for a typical 18 m² garage roof in torch-on felt, at South East guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.

Can I paint or coat an old felt roof?

Reflective or liquid coatings can extend the life of a sound felt roof, but they will not fix wet insulation, a rotten deck or poor falls. A survey shows whether coating or replacement makes more sense.

Why does my felt roof have blisters?

Blisters usually form when moisture or air trapped beneath the felt expands in the sun. A few small, intact blisters may be monitored, but widespread or split blisters point to a repair or replacement.

Other flat roof work in Windsor

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

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