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Flat roof systems

Torch-on felt roofing in Borehamwood

Torch-on felt in Borehamwood is a layered roof: an underlay, sometimes an intermediate sheet, and a mineral-faced cap sheet, each heat-bonded to the one below. It is generally the most economical of the main systems and suits garages, extensions and larger roofs on blocks and shops alike.

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

Borehamwood at a glance

Postcode districts
WD6
Population
about 36,322 (GeoNames)
Council area
Hertsmere Borough Council
Building approval
Hertsmere Borough Council building control, or a registered building control approver
Nearest main town
Watford, about 5 miles
Guide price region
East of England (+5% on West Midlands rates)

Why choose torch-on felt roofing in Borehamwood?

Torch-on felt suits property owners in Borehamwood 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.

Borehamwood's flat roofs are mostly on lock-up garage blocks on estates, with plenty on bungalows with flat-roofed side extensions and dormers too. The East of England is the driest part of Britain, with parts of the Anglian region around 630 mm a year, so summer heat and UV, not rainfall, do most of the ageing on a felt roof.

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

Guide price in Borehamwood: £1,600–£2,750 for a typical 18 m² garage roof in torch-on felt, including VAT at East of England 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£1,600–£2,750
Extension (20 m²), felt, new deck + insulation£2,850–£4,900
Block of flats (150 m²), felt + insulation + scaffold£16,350–£28,550
Single garage (18 m²), EPDM rubber£1,700–£2,950
Extension (20 m²), EPDM, new deck + insulation£2,950–£5,150

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
  • 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 Borehamwood: questions

Do you cover Borehamwood?

Yes. Borehamwood is part of our Hertfordshire coverage, including postcode districts WD6. 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 Borehamwood?

Where the work needs approval it goes to Hertsmere Borough Council 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 Borehamwood?

£1,600–£2,750 for a typical 18 m² garage roof in torch-on felt, at East of England 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.

Can torch-on felt go over an existing felt roof?

Sometimes, if the old roof is dry, well bonded and the deck is sound. Often stripping is better, because overlaying can trap moisture and hide rot; our guide to overlay or strip explains how we decide.

Other flat roof work in Borehamwood

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

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

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