Felt Roofing

Modern torch-on felt systems are a different animal to old-school felt roofs. Three-layer systems with 15-25 year lifespans, ideal for garage roofs, dormers and budget-conscious installations.

Types of felt roofing

High-performance torch-on felt (3-layer)

The current standard. Three layers of modified bitumen felt, torch-applied to create a fully-bonded waterproof membrane.

• Lifespan: 15-25 years
• Cost: £45-£70 per m² installed
• Pros: Cheapest long-lasting option, quick install, well-understood by UK trades

Self-adhesive felt

Modern peel-and-stick systems. No torch required — safer for confined spaces and some applications.

• Lifespan: 15-20 years
• Best for: Smaller roofs, areas where torch work is impractical

Traditional pour-and-roll (rare today)

Older method using hot bitumen. Less common in modern installations but we still maintain and repair these systems.

When felt is the right choice

• Budget is the primary concern — felt is the cheapest modern flat roof system
• Garage or outbuilding — appropriate for low-priority structures
• Patch repair — existing felt roof with localised damage
• Speed of install matters — felt goes down fast

When felt isn't ideal

• You want 30+ year lifespan (use EPDM)
• Walkable surface needed (use GRP)
• Multiple previous failures (consider upgrading the system)
• Conservation area (slate or heritage-appropriate materials preferred)

Common felt problems

• Blistering — trapped moisture vapour, usually poor ventilation
• Splitting at seams — failed laps or shrinkage
• Ponding — inadequate falls allowing water to sit
• Edge failure — trims or fillets failing
• Age failure — bitumen becomes brittle after 15+ years

Cost guide

• Garage roof (15-20m²): £1,200-£1,800
• House extension (20-40m²): £1,600-£3,000
• Large flat roof (50m²+): £3,500-£5,500

Warranties

• Material warranty: 10-15 years (manufacturer)
• Workmanship warranty: 5 years from us