Garage Roof Replacement Cost: Felt, EPDM and GRP Options

A garage roof is the cheapest flat roof you will ever replace and the one most likely to spring a surprise on you. The covering itself is a small job. What drives the garage roof replacement cost is what the roofer finds when the old felt comes off, and whether the sheet you are removing contains asbestos. This guide covers what the job should cost, what legitimately adds to it, and where quotes go wrong.

What a garage roof replacement costs

Broad 2026 ranges, supplied and fitted:

• Single garage: roughly £750 to £2,000
• Double garage: roughly £1,000 to £3,500

By material, per square metre:

• Felt: roughly £50 to £80
• GRP (fibreglass): roughly £70 to £110
• EPDM rubber: roughly £80 to £120

Flat felt or rubber garage roofs usually take one to two days. A pitched garage roof can take three.

Location moves this more than people expect. Labour rates in London and the South East run roughly 20% to 35% above the North or Wales, so a job at £1,200 in the Midlands can be £1,600 in London for identical work.

Our flat roof cost comparison calculator will run your own measurements, and flat roof cost UK covers the wider picture across extensions and dormers.

Which material for a garage, specifically

The general flat roof arguments are in our best flat roof material guide. What is different about a garage:

Nobody walks on it. That removes GRP’s main advantage. GRP earns its premium on balconies and terraces where the hard surface takes foot traffic. On a garage roof you are paying for a property you will not use.

It is usually detached from your heating. A garage is unheated, so the condensation and warm-roof insulation questions that complicate an extension roof mostly do not apply. That keeps the build-up simple and the cost down.

It is out of sight. Appearance carries less weight than on a roof you look at from a bedroom window.

Add those up and EPDM is the sensible default for most garages. It goes down as a single sheet with no seams to fail, it tolerates the ponding that garage roofs are prone to, and it is the cheapest option across a full lifespan even though felt is cheaper on the day.

Felt still makes sense in one case: you are selling, or the garage itself is near the end of its life and you want ten years, not forty. That is a legitimate decision, not a compromise.

The asbestos question

This is the garage-specific cost, and the one that turns a £900 job into a £3,000 one.

Corrugated cement sheet garage roofs, common on garages built from roughly the 1950s to the mid 1980s, frequently contain asbestos. If yours is corrugated grey sheet rather than felt on timber, assume it does until tested. An asbestos survey costs somewhere around £325. Replacing an asbestos garage roof commonly lands between about £950 and £3,750 or more, depending on size, access and what goes back on.

Do not take it off yourself. Asbestos cement is legally non-licensed work, which is where homeowners get misled: non-licensed does not mean unregulated or safe for amateurs. The HSE is explicit that you should not try to repair or remove asbestos materials if you have not had training for non-licensed asbestos work, and that domestic householders should use trained professionals. The distinction is that a trained contractor may do the work without a licence, not that anyone may.

Two things follow that people miss:

1. Asbestos waste is hazardous waste. It cannot go in a skip or with household waste and must be disposed of legally. Your local authority can tell you the route. A quote that does not itemise disposal is a quote to worry about.
2. Sheet in good condition can be left alone. HSE’s own advice is that undamaged material in good condition is often best left in place. If your cement roof is intact and not leaking, “replace it because asbestos” is not automatically the right call. Removal creates the risk; leaving it undisturbed does not.

If in doubt, your council’s environmental health officer will advise, free.

The deck: where the quotes diverge

Here is why two quotes for the same garage can differ by £600.

A flat garage roof is a covering on a timber deck. The covering is what failed; the deck is what has been getting wet since it failed. Until the old felt is off, nobody knows whether the boards underneath are sound. Roofers handle that uncertainty in two ways:

• Quote for the covering only, then charge for deck repairs as an extra when they find them. Looks cheaper. Often is not.
• Quote inclusive of a new deck, or with a stated allowance. Looks dearer on paper. No nasty phone call on day two.

Neither is dishonest, but they are not comparable, and the cheaper-looking quote is frequently the one that ends up costing more. Ask every roofer the same question: what happens if the deck is rotten, and is that in this price? Get the answer in writing.

Other extras that are legitimate: new drip trims and edge detail, a replacement outlet, disposal of the old covering, and scaffolding or an edge protection system if the garage is high or the access is awkward. A single-storey garage rarely needs full scaffold, so a quote carrying a big scaffolding line deserves a question. See our roof scaffolding cost guide for what is reasonable.

Getting a quote you can trust

Ask for it in writing, itemised, with:

• the material and system by name, not just “rubber”
• whether deck replacement is included or excluded, and the rate if extra
• disposal, and for asbestos, the disposal route
• the guarantee, and whether it covers workmanship or only the membrane
• VAT status

Our guides on how to read a roofing quote and questions to ask a roofer go further, and both apply to a small job as much as a big one.

Frequently asked questions

How much does it cost to replace a garage roof in the UK? Roughly £750 to £2,000 for a single garage and £1,000 to £3,500 for a double, supplied and fitted, depending on material and region. Per square metre, felt runs about £50 to £80, GRP about £70 to £110 and EPDM about £80 to £120. An asbestos cement roof pushes the job to roughly £950 to £3,750 or more.

What is the best material for a garage roof? EPDM rubber for most garages. It has no seams to fail, copes with ponding water, and is the cheapest option measured across its full lifespan. GRP’s advantage is that it takes foot traffic, which a garage roof does not need, so you are paying for something you will not use.

Can I remove an asbestos garage roof myself? You should not. HSE advises against removing asbestos materials without training for non-licensed asbestos work, and recommends householders use trained professionals. Asbestos cement is classed as non-licensed work, which means a trained contractor can do it without a licence, not that an untrained homeowner can. The waste is hazardous and cannot go in a skip.

How do I know if my garage roof contains asbestos? If it is corrugated grey cement sheet and the garage dates from roughly the 1950s to the mid 1980s, assume it does until a survey says otherwise. A survey costs in the region of £325. Felt on a timber deck is not asbestos.

Should I replace an asbestos garage roof that is not leaking? Not necessarily. HSE’s position is that asbestos material in good condition is often best left undisturbed, because removal is what releases fibres. If the sheet is intact and the roof is doing its job, leaving it alone is a legitimate choice. Your council’s environmental health officer can advise.

Why do garage roof quotes vary so much? Usually the timber deck. Nobody can see its condition until the old covering is off, so some roofers quote for the covering alone and charge for rot as an extra, while others include a new deck or an allowance. Ask each one directly whether deck replacement is in the price.

How long does a garage roof replacement take? One to two days for a flat felt or EPDM roof. Up to three days for a pitched garage roof. Asbestos removal adds time for the controlled strip and disposal.