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Flat roof systems

Torch-on felt roofing in Horsham

Across West Sussex, including Horsham, we use torch-on felt on roofs where a proven, multi-layer system makes sense. The surveyor checks the deck, the falls and any timber near the edges before recommending two or three layers, and every detail is set out in your fixed written quote.

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

Horsham at a glance

Postcode districts
RH12
Population
about 51,472 (GeoNames)
Council area
Horsham District Council
Building approval
Horsham District Council building control, or a registered building control approver
Nearest main town
Crawley, about 7 miles
Guide price region
South East (+10% on West Midlands rates)

Why choose torch-on felt roofing in Horsham?

For a commercial roof in Horsham, such as a shop, surgery or club, torch-on felt offers a hard-wearing mineral finish that takes occasional maintenance traffic. Phased work keeps part of the building weathertight while the rest is re-roofed, so the business can usually keep trading.

Around Horsham, flat roofs are common on 1930s semis with flat-roofed garages and kitchen extensions and on newer estates where the first extension roofs are now being replaced. 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 Horsham?

For Horsham 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?

  • Deck inspection with replacement of damaged boards
  • Strip-off of the existing roof covering and removal of waste
  • Mineral-finished cap sheet, upstands, outlets and edge trims
  • Vapour control layer and warm-roof insulation where needed

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 Horsham: questions

Do you cover Horsham?

Yes. Horsham is part of our West Sussex coverage, including postcode districts RH12. 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 Horsham?

Where the work needs approval it goes to Horsham District 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 Horsham?

£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.

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.

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.

Other flat roof work in Horsham

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

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

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