Of all the roofs on a property, the garage is usually the cheapest to redo, and published prices bear that out: a single flat garage costs a fraction of what a house roof does. The spread is still wide, because the covering, the deck beneath it and the presence of asbestos cement sheeting change the work far more than the floor area does. Below are the figures third-party cost guides publish for UK flat garages, pitched garages and asbestos removal, followed by an account of what sits behind each number, so a quote can be read item by item. None of them is an Empire price. Use them to check that a quote is complete rather than to predict yours. Your own figure follows a survey, when we look at the roof and photograph what is actually there.
What a garage roof typically costs in the UK
Cost guides usually split garage roofs by shape and by garage size. The figures below come from MyBuilder's garage roof replacement guide (2026) and its asbestos removal guide (2026), and are typical UK ranges. A Bath job can land either side of them.
| Item | Typical UK range |
|---|---|
| Single garage, flat roof | £700 to £1,000 |
| Double garage, flat roof | £900 to £1,400 |
| Pitched garage roof | £2,500 to £4,500 |
| Asbestos removal, average | About £2,000 |
| General asbestos removal, per m² | About £50 |
Your fixed quote follows the survey. Treat the table as a yardstick, not a price list.
Two things stand out. A flat garage roof is cheap partly because it is a single plane with few edges, and a double garage costs only a little more than a single because the extra area is the quick part of the job. A pitched roof costs much more because it has tiles or slates, timber to carry them, and a ridge, verges and flashings to finish. Asbestos is a separate line again, and it can matter as much as the new covering, so the sections below take each in turn.
Where a guide gives a range, the low end usually assumes an easy roof: a sound deck, easy access and no hidden defects. The top end assumes the opposite. Few garage roofs are wholly one or the other, which is why the survey matters.
Flat garage roofs: covering, deck and falls
A flat garage roof is priced by the covering laid over a timber deck. The deck is the boarding that carries the membrane, usually plywood or OSB on joists. MyBuilder's flat roof cost guide (2026) reports typical UK rates of, per m², £70 to £100 for bitumen felt, £90 to £130 for EPDM and £95 to £150 for GRP. EPDM is a synthetic rubber, delivered as one large sheet trimmed to the roof. GRP means glass-reinforced plastic, a fibreglass skin formed on site from liquid resin. The three are set side by side for cost and life on our garage roof materials page.
The rate is for the covering. It does not usually include a new deck, and the deck is where garage quotes diverge. If the boards under the old felt are damp, soft or delaminating, they have to be renewed before anything is laid over them, or the new membrane will fail at the same places. Replacing a deck adds timber, labour and time. A roofer who quotes without lifting a corner of the old covering to look is guessing.
Falls matter too. Water must run to the gutter, and pools of standing water shorten the life of any covering. Manufacturers working to BS 6229:2018 recommend a design fall of 1:40, so that the finished roof drains at no less than 1:80 once the deck has settled. Many older garage roofs were laid almost level, and correcting that means adding tapered battens or firring strips, which is extra work and extra cost. Where the roof already holds water, ask whether the quote includes correcting the fall.
Edges finish the job: the drip trim over the gutter, the upstand where the garage meets a house wall, and the flashing that closes that gap. These are small in area and large in consequence, and they are where leaks start on an otherwise sound roof.
Pitched garage roofs: why the range is higher
A pitched garage roof is typically £2,500 to £4,500 on the MyBuilder garage roof guide (2026). The gap from a flat roof reflects the materials and the number of components. A tiled or slated roof needs battens, the small timbers fixed across the rafters to carry the tiles, an underlay beneath them, the tiles themselves, and a ridge along the top. At the gable end the roof finishes in a verge, and that edge has to be fixed so wind cannot get under it.
BS 5534:2014 expects ridge and verge tiles to be fixed mechanically, because a mortar bed on its own is not relied on. One common answer is dry-fix, where clips and a ventilated strip replace the mortar. MyBuilder's dry ridge guide (2026) reports a typical UK range of £40 to £60 for each linear metre of dry ridge. On a short garage ridge that is a modest line, but it is one to look for on the quote.
Against a house wall, the roof edge is closed off with a flashing: lead tucked into the brickwork and lapped over the tiles. Lead is graded by a code that sets its thickness: Leadworx gives code 4 as 1.80 mm and code 5 as 2.24 mm, and Royston Lead lists both codes for flashings. The right code depends on the job. A cheap quote may leave out the lead and rely on sealant, which will not last as long.
Our guide to pitched garage roofs explains how re-tiling is done step by step, and when repair is enough. The cost question for a pitched garage is usually whether the timbers are sound, because rafters that have rotted at the wall plate change a re-tile into a partial rebuild.
Asbestos cement roofs: testing, removal and disposal
Many older garages are roofed in corrugated sheets of asbestos cement. If yours is one, the price has an extra component that the cost guides treat separately. MyBuilder's asbestos removal guide (2026) gives an average of about £2,000 for removal, and puts general removal at about £50 for each square metre. These are national averages for a range of jobs, not a price for a garage, so use them only to judge the order of magnitude.
Three costs sit inside that line. The first is confirming what the sheets are. A sample sent to a laboratory removes guesswork, and our page on whether your garage roof is asbestos explains the signs. The second is the removal itself, which is slower than stripping an ordinary roof because the sheets have to come off whole and be packed and labelled. The third is disposal at a site that accepts asbestos waste, which is not the household tip.
HSE guidance places careful removal of asbestos cement sheeting in the non-licensed category, on condition that the sheets come away unbroken. If they are going to be broken up and release significant dust and debris, HSE treats the job as notifiable non-licensed work. That distinction affects the method and the paperwork, and so the price. Our guide to asbestos garage roofs goes through how the work is done.
Overlaying new sheeting on asbestos cement avoids disposal, but it leaves the problem in place and changes how the building is handled later. Ask any roofer who proposes it to explain what happens at the next re-roof.
What moves a garage roof quote up or down
Two quotes for the same garage usually differ because of six factors.
- Size and shape. Area sets the quantity of covering. A garage with a hipped end, a lean-to or a parapet works out dearer by the square metre than a plain rectangle.
- Access. A detached garage at the end of a drive is simple to reach. One tight against a boundary, or behind a house, can mean carrying materials by hand and using a tower in place of a ladder.
- The deck or timbers. Sound boarding keeps the price near the low end. Rot does the opposite.
- Strip or overlay. Laying a new membrane over an old one saves the cost of stripping and tipping. It is only sensible when the old covering is dry and firmly adhered.
- Edges and extras. Fascias, gutters, flashings and trims. Our page on garage gutters covers the guttering side.
- Waste. MyBuilder's new roof guide (2026) puts disposal on a house roof at £100 to £1,000 as a typical figure. A garage produces much less, but a skip or a van load is still a line.
A garage that is being converted into a room is a different brief. The roof then has to meet thermal and fire requirements that an ordinary garage does not, and the cost climbs accordingly. The garage conversion roof page deals with that brief.
Repair belongs in the comparison. A small leak at a joint or a split in a membrane may need a patch, not a new roof, and we repair where repair works. MyBuilder's roof repair guide (2026) puts minor repairs at £100 to £300 as a typical UK figure, which is why a straight answer on whether to patch or replace can save a good deal.
How to read a garage roof quote
A good garage roof quote lists its parts. Look for the covering and its thickness or grade, the deck work (renewed, repaired or kept), the falls, the edge trims and flashings, the guttering, stripping the old roof and taking it away, and what is excluded. A single line reading "re-roof garage" with a total tells you nothing and leaves room for argument later. If asbestos is suspected, the quote should say who tests it, how it is removed and where it goes.
Our survey is free and covers the points above. We go up, lift a corner of the old covering where we can and check the deck and the edges, photographing your roof as we go so the evidence is yours to look at. A fixed price in writing follows, listing each element of the work separately. The workmanship is covered by a written 10-year guarantee.
Planning and Building Regulations are the other question a quote should settle. A simple matching re-cover of a detached garage is unlikely to raise either, but a conversion, a change of height or a change in appearance can. If the house or the garage sits in a listed setting in Bath, speak to B&NES Council before work starts, since a listed building consent application is made separately from any planning application. Where Building Regulations apply, we say what is required and deal with the notification. For the rules on that, see our page on garage roof replacement.