Torch-on Felt Roof Costs UK 2026
Torch-on felt remains the most popular and cost-effective flat roofing solution in the UK. When installed as a 3-layer high-performance system, it provides a durable, puncture-resistant finish that can last over 25 years.
The 3-Layer System Breakdown
In 2026, a standard "felt roof" is no longer just one layer of tar paper. A professional installation involves a sophisticated three-layer buildup that manages both moisture and structural movement.
Mineral Cap Sheet (4-5mm)
The protective top layer with stone granules to prevent UV damage and foot traffic wear.
Reinforced Underlay (2-3mm)
A high-tensile polyester layer that provides the primary waterproof seal.
Venting Base Layer
A perforated sheet that allows the wooden deck to "breathe," preventing air blisters.
Average Costs 2026
| Repair / Install Type | Typical Cost |
|---|---|
| Patch Repair (Small Leak) | £150 – £350 |
| Standard Flat Garage (15m²) | £900 – £1,400 |
| 3-Layer SBS System (per m²) | £50 – £95 |
| Full Replacement with Decking | £120 – £180/m² |
*Prices are national UK averages for 2026. London and South East premiums of 20-30% apply.
Fire Safety & Cold-Applied Systems
Many insurance companies now discourage the use of gas torches on domestic roofs. **Cold-applied felt** systems use high-strength adhesives instead of heat. While they cost roughly 15% more in materials, they offer the same 25-year lifespan with significantly less risk to your property.
SBS vs Standard Bitumen
When choosing a felt system, the chemical composition matters more than the thickness. Standard oxidized bitumen is prone to cracking in the winter. **SBS Modified Bitumen** is rubberized, allowing it to stretch and contract with the UK's temperature swings without failing.
Durability
SBS systems are 3x more elastic than standard felt, making them less likely to split over board joints.
Warranty
Most 3-layer SBS installs come with a 20-25 year manufacturer guarantee compared to just 10 years for standard felt.
Felt Roofing FAQ
Calculate Your Felt Roof Cost
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