Garage Roof Repair & Replacement Cost UK (2026 Guide)

The garage roof is easy to overlook — until it starts to leak. Whether you have a detached single garage, a double garage or an integral garage beneath a room, a failing roof can cause serious damage to vehicles, stored belongings, and the structure of the building itself. The good news is that garage roofs are generally simpler and cheaper to repair or replace than a full house roof.

This guide covers garage roof repair and replacement costs across the most common materials in the UK in 2026.

Garage Roof Cost: Quick Summary

All prices are for supply and installation. Regional variation applies — London and the South East typically costs 20–30% more.

Most Common Garage Roof Types

Felt (Built-Up Bitumen)

Traditional mineral felt is the most common material on older UK garages. It's cheap and quick to install but has a relatively short lifespan — typically 10–15 years before replacement is needed. Common failure modes include blistering, cracking and splitting at joints, particularly after hot summers followed by cold winters.

A full felt replacement on a standard single garage (typically around 15m²) costs £800–£1,800 depending on the condition of the underlying deck and how many layers of old felt need stripping.

EPDM Rubber Membrane

EPDM has become the preferred replacement for felt in most of the UK. It's a single-ply rubber membrane that's highly durable, flexible in all temperatures and carries a lifespan of 30–50 years when properly installed. It's more expensive than felt upfront but offers dramatically better longevity and lower maintenance costs.

A standard single garage EPDM roof typically costs £1,200–£2,500.

GRP Fibreglass

Glass reinforced polyester (GRP) is a rigid, seamless surface that's particularly good at handling ponding water. It's the premium flat roof option and is well-suited to garages where the roof may double as a balcony or terrace. It requires skilled installation but lasts 25–30+ years with minimal maintenance.

Expect to pay £1,500–£3,000 for a single garage GRP roof.

What Affects the Cost?

Size — The most obvious cost driver. Prices are largely calculated per square metre for materials, plus a base labour cost. A double garage (typically 25–35m²) costs proportionally more than a single (12–18m²).

Deck condition — The timber or concrete deck beneath the roofing material may need repair or replacement. Rotten OSB or plywood boarding is a common finding when stripping old felt and can add £200–£500 to the job.

Drainage — Poor drainage (guttering falling away, blocked outlets) that has caused prolonged water saturation is likely to have damaged the deck and possibly the structural timbers below. Addressing drainage at the same time as re-roofing is sensible.

Access — Most detached garages are easy to access without scaffolding. Integral garages or those adjacent to the house may require more care or access equipment.

Disposal — Stripping and disposing of old mineral felt adds a small amount to the cost. Some roofers include this; others quote it separately.

Repair or Replace?

A targeted repair makes sense when:

• The roof is relatively new (under 10 years old) and damage is isolated
• A split or blister has appeared following a specific event (impact, extreme weather)
• Only flashing or edge details have failed

Full replacement makes sense when:

• The felt is more than 15 years old and showing widespread crazing or cracking
• You've had repeated leaks in different locations
• The deck beneath has water damage

A good roofer will give you an honest assessment. Be wary of anyone who pushes full replacement on a roof that could reasonably be repaired, or conversely recommends repeated patching on a roof that needs replacing.

Signs Your Garage Roof Is Failing

• Water stains on the garage ceiling or walls
• Visible cracks, splits or blistering on the roof surface
• Soft or springy areas underfoot (indicating deck damage)
• Moss or algae growth across the surface
• Sagging or ponding water that sits for days after rain
• Lifting or separating felt at the edges

Finding a Reliable Roofer for Garage Work

Garage roof replacement is a common job for most flat roofing contractors. When getting quotes:

• Make sure the price includes stripping the old material and disposal
• Ask whether the deck will be inspected and priced for repair if needed
• Get at least two or three written quotes
• Ask about the guarantee — a reputable EPDM or GRP installer should offer a minimum 10-year guarantee on materials and workmanship

Find a trusted flat roofing specialist in your area at Local Roofer Directory.

FAQ

How long does a garage roof replacement take? Most single garage roof replacements take one day. A double garage or complex job with deck repairs may take two days.

Can I repair a garage roof myself? Minor repairs using bitumen roof paint or lap sealant are possible for a capable DIYer. However, a full replacement should be left to a professional — proper substrate preparation and correct membrane installation are critical to a long-lasting result.

Does a garage roof need building regulations approval? Replacing like-for-like does not require building regulations approval. However, if you're increasing insulation levels as part of a warm roof installation, some local authorities may want to see compliance with thermal performance requirements.

Is my garage roof covered by home insurance? Storm damage and sudden unexpected events are typically covered. Wear and tear is not. If your garage roof has failed due to age or lack of maintenance, you'll usually need to fund repairs yourself.