Question answered
What is the cheapest way to replace a garage roof?
The short answer
On a flat garage the lowest outlay is usually felt or EPDM, and typical UK prices for the two overlap. Felt tends to have the shortest life, so over the years EPDM or GRP can work out lower per year of service. Weigh each option by price and expected life together, and confirm that each quote states if VAT and scaffolding are included.
The lowest price on the day and the lowest cost over twenty years are rarely the same quote. Here is how the garage roof options compare, and where a saving turns into a second bill.
Price today against price per year
A garage roof is a small area, so the gap between the lowest and highest quote can look tempting. The better test is cost across the life of the covering. Divide each price by the years you can reasonably expect from it, then add anything you would pay for twice, such as a second scaffold hire or a repair in year eight. Our garage roof replacement service page shows the full range of options.
MyBuilder's garage roof replacement guide (updated 21 August 2026) gives typical UK ranges of £700 to £1,000 for a single flat garage roof, £900 to £1,400 for a double and £2,500 to £4,500 for a pitched one. Checkatrade puts a re-felt at around £1,000 to £2,000, averaging £1,500. Those are national figures, so use them to judge a quote rather than reading them as a price for yours.
What moves the number on any garage is its size, whether the deck underneath is sound, how easily materials reach the roof, and how readily the old covering strips off. The survey finds those things, and our written quote follows it as one total price.
Felt, EPDM and GRP compared on a flat garage
Three coverings do most of the work on a flat garage. Torch-on felt is bitumen sheet melted on in layers. EPDM is a single rubber membrane, usually stuck down with adhesive. GRP is a fibreglass and resin skin built up on site.
MyBuilder's guide gives typical UK rates of about £75 per m² for felt, £70 to £100 per m² for EPDM and about £125 per m² for GRP. Felt and EPDM sit close together on price, then part company on life. Less's flat roof guide (March 2026) quotes 10 to 20 years for felt, with the comment that careful laying can reach 20 while a poor job fails in under 10, against 25 to 40 years for GRP. GreenSpec gives 20 to 30 years for EPDM. Workmanship and upkeep decide where a given roof lands.
So the lowest price per square metre is not automatically the lowest cost per year. If you expect to keep the garage for ten years or more, a membrane or GRP that lasts longer often comes out level or ahead. Our page on garage roof cost goes through the figures.
Pitched garages and sheet roofs
A pitched garage costs more to start with because it needs timber work, a covering and ridge or verge details. In return a tiled pitched roof can run for decades. Marley's figure for concrete tiles is around 60 years, though it says that is no guarantee, while MyBuilder puts the replacement point for concrete tiles at 30 to 50 years. On a garage you plan to keep, the yearly cost can be low even when the first invoice is not. A pitched roof also leaves room to store things in the roof space later, which a flat roof does not.
Many older garages carry large corrugated or flat sheets instead. Swapping one cracked sheet looks like the lowest-cost fix, and on a modern fibre-cement or metal roof it can be. On an older garage a sheet may contain asbestos, and breaking or drilling it is what to avoid. Our page on replacing one garage roof sheet explains when that is a sensible job and when it is not.
Savings that bring the cost back later
Some economies look sound and fail within a few winters. New felt laid over a wet or soft deck seals the damp in and cuts years off the whole roof. Leaving out edge trims exposes the perimeter to wind and driving rain, and sea weather finds loose edges quickly. Skipping the fall, the slope that sends rain towards the gutter, produces ponds that age any covering faster.
Flat roofs are normally laid to a design fall of 1:40 so that the finished roof keeps at least 1:80 after allowing for settlement and sag, a figure IKO gives from the 2018 edition of BS 6229 (since revised). A low quote that ignores this has saved money on the part you cannot see once the roof is finished.
The same goes for patching an old roof close to the limit of its life. A patch that holds for a season is fair value on a young roof with a dry deck. It is poor value where several repairs already exist, because each one buys less time than the last.
When asbestos cement changes the sum
HSE says to presume asbestos is present in older garages, meaning any dating from before 2000. For a garage with cement sheets, that assumption affects the price more than the choice of new covering does. MyBuilder's asbestos removal guide quotes £350 to £1,295 for a single garage roof and £650 to £1,800 for a double, and Checkatrade gives £950 to £3,750 for removal and disposal. All of that comes before the new roof. Disposal is a large item, so a sample result showing the sheets are clean can change the whole decision.
HSE's roof guidance raises covering the sheets with a non-asbestos product as an alternative to taking them down. That is not always possible, since the structure must carry the extra weight and be safe to work on, but where it is possible it can reduce the handling and the waste. Read how to tell if a garage roof is asbestos first, then whether removal needs a licence.
Low-cost garage roofs: two more questions
Is it worth re-felting a flat garage roof one more time to save money?
It can be, when the deck is dry and sound and the existing felt is in its later years. A fresh layer is the least work that properly stops the leak. If the boards are soft, or a second layer has already gone on, the saving is false, because the deck is the real problem.
Does a lower garage roof quote usually leave something out?
Not necessarily, but check. Ask whether it includes VAT and scaffolding, where the old covering and the waste end up, and whether any deck repair is allowed for. A quote that names each of those in writing is easier to compare than one that stays silent.
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