- Price per m²
- £62–£108
- Typical life
- 15–25 years
- Manufacturer guarantees
- 10–20 year material guarantees on specified systems
- Typical garage roof
- £1,550–£2,700
Bristol at a glance
- Largest towns
- Bristol
- Postcode areas
- BS
- Building control
- Bristol City Council
- Neighbouring areas
- Somerset · Gloucestershire · Wiltshire · Herefordshire
- Guide price region
- South West (+3% on West Midlands rates)
How much does a torch-on felt roof cost in Bristol?
Guide prices including VAT at South West rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Single garage (18 m²), torch-on felt | £1,550–£2,700 |
| Extension (20 m²), felt, new deck + insulation | £2,800–£4,850 |
| Block of flats (150 m²), felt + insulation + scaffold | £16,000–£28,000 |
| Single garage (18 m²), EPDM rubber | £1,650–£2,900 |
| Extension (20 m²), EPDM, new deck + insulation | £2,900–£5,050 |
Which flat roofs are common in Bristol?
Flat roofs in Bristol sit on terraced streets with flat-roofed rear kitchens and bathrooms, 1960s and 1970s link-detached houses with flat-roofed garages and porches and 1930s semis with flat-roofed garages and kitchen extensions. The South West averages roughly 1,260 mm of rain a year and many roofs face wind off the Atlantic, so we specify fixings and edge details for wind uplift as well as drainage. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in England
Replacing more than half of a roof over a heated room usually counts as renovating a thermal element, so it is insulated to current standards and notified to building control. Renovated roofs over heated rooms are insulated to around 0.16 W/m²K where that's feasible, and new extension roofs are built to 0.15 W/m²K. In Bristol the application goes to Bristol City Council. More on the rules.
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.
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.
Which towns in Bristol do we cover?
Torch-on felt roofing in Bristol: questions
Which towns in Bristol do you cover?
All of Bristol. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a torch-on felt roof cost in Bristol?
£1,550–£2,700 for a typical 18 m² garage roof in torch-on felt, at South West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which council handles building control for a flat roof in Bristol?
It depends on where the roof is: in Bristol that's Bristol City Council. Replacing more than half of a roof over a heated room usually counts as renovating a thermal element, so it is insulated to current standards and notified to building control. We confirm which applies at the survey.
Is torch-on felt better than the old felt roofs?
Yes, considerably. Modern torch-on membranes are polymer-modified and polyester-reinforced, laid in bonded layers, and typically last much longer than the older felt systems they replace.
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.
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.
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