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Flat roof systems

Torch-on felt roofing in Northampton

For blocks of flats, shops and houses in Northampton, torch-on felt remains a practical way to re-roof at a sensible cost. Each job follows the same pattern: survey, written quote, strip and lay, then a fire watch and a walk-round with you before we hand over the written workmanship guarantee.

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

Northampton at a glance

Postcode districts
NN1, NN2, NN3, NN4, NN7
Population
about 245,899 (GeoNames)
Council area
West Northamptonshire Council
Building approval
West Northamptonshire Council building control, or a registered building control approver
Nearest main town
Milton Keynes, about 15 miles
Guide price region
East Midlands (−2% on West Midlands rates)

Why choose torch-on felt roofing in Northampton?

Torch-on felt is widely specified for blocks of flats and HMOs, in Northampton 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.

In and around Northampton, flat roofs are typically found on terraced streets with flat-roofed rear kitchens and bathrooms, and on shops with flat-roofed rear stores below flats. The East Midlands is drier than the west of Britain, so most flat roofs here fail through age, UV and poor detailing at upstands rather than sheer rainfall.

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

At East Midlands guide rates, a typical 18 m² garage roof in torch-on felt comes to £1,500–£2,550 including VAT. The fixed price comes after a free survey for new and replacement roofs.

JobGuide price inc VAT
Single garage (18 m²), torch-on felt£1,500–£2,550
Extension (20 m²), felt, new deck + insulation£2,650–£4,600
Block of flats (150 m²), felt + insulation + scaffold£15,250–£26,650
Single garage (18 m²), EPDM rubber£1,550–£2,750
Extension (20 m²), EPDM, new deck + insulation£2,750–£4,800

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
  • Two- or three-layer reinforced bitumen membrane with staggered laps
  • 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 Northampton: questions

Do you cover Northampton?

Yes. Northampton is part of our Northamptonshire coverage, including postcode districts NN1, NN2, NN3, NN4, NN7. 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 Northampton?

Where the work needs approval it goes to West Northamptonshire 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 Northampton?

£1,500–£2,550 for a typical 18 m² garage roof in torch-on felt, at East Midlands guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.

Is torch-on suitable for a block of flats?

Yes, layered bitumen systems are widely used on blocks of flats and commercial buildings. Larger roofs often use three layers and insulation, with hot works planned around residents.

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 Northampton

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

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

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