Felt roof explained: types, lifespan and cost

Torch-on felt vs self-adhesive felt. Which lasts longer and costs less?

Quick answer: Torch-on felt (three-layer system) lasts 10-20 years and costs £30-40/m² installed. Self-adhesive felt (for sheds) lasts 5-10 years and costs £10-20/m². Torch-on is better for garages and extensions. Self-adhesive is sufficient for garden sheds.

Last reviewed: 2026-05-16 · 5 min read · Verified against 4 sources

What is felt roofing?

Felt roofing is layers of bitumen-impregnated fabric overlapped and bonded to form a waterproof membrane. Modern roofing felt uses polyester or fibreglass base (stronger than old paper-based felt). Two main types: torch-on (heat-welded) and self-adhesive (peel-and-stick).

Torch-on felt lifespan: 10-20 years
Self-adhesive felt lifespan: 5-10 years
Typical cost installed: £10-40/m²

How long does a felt roof last?

Three-layer torch-on felt lasts 10-20 years per Checkatrade data. Single-layer self-adhesive shed felt lasts 5-10 years. Lifespan depends on UV exposure and foot traffic. A south-facing garage roof degrades faster than a north-facing shed roof.

How much does a felt roof cost?

Torch-on felt: £30-40/m² installed (three-layer system). Self-adhesive felt: £10-20/m² materials only (DIY). A 15m² shed roof costs £150-300 for self-adhesive or £450-600 for torch-on.

Torch-on vs self-adhesive felt

Torch-on is heat-welded with a blowtorch. Three layers (base, intermediate, cap sheet) overlapped and bonded. More durable, lasts 10-20 years, needs professional installation. Self-adhesive is peel-and-stick. One or two layers. Easier to install, lasts 5-10 years, suitable for sheds only.

Sources

Checkatrade, Flat roof felt cost guide, accessed 16 May 2026
Which?, Felt roofing options, accessed 16 May 2026
IKO, Torch-on felt product data, accessed 16 May 2026
NFRC, Felt roofing standards, 2024

Last reviewed: 2026-05-16