What is the average cost of replacing a garage roof?

Checkatrade's roof replacement guide (updated October 2026) gives £1,000 to £2,000 for re-felting a garage, averaging £1,500. That is the closest thing to a headline number for the most frequent job: strip a tired flat felt roof and lay new felt on a deck that is still sound. Re-felting means fresh layers of bitumen felt, normally torch-on, where a flame softens the underside so it fuses to what lies beneath.

Checkatrade's flat roof replacement table runs from £2,800 to £7,500 and carries the heading "(+VAT)". Those totals sit higher because they take in flat roofs of all sizes, extensions included, and allow for extras a basic re-felt leaves out, such as new boards, new edge trims and insulation. A single garage tends to sit towards the lower end of that spread, while a broad double garage with a rebuilt deck can reach the upper part.

Nothing in the garage re-felt figure says whether VAT is in it, so ask every roofer to state it on paper. Twenty per cent is a big gap on a bill this size.

Pitched garages work out differently. A tiled or slated garage is priced like a small house roof, so the covering, the timbers and the length of ridge and verge set the sum. Our page on garage roof replacement lists the garage roofs we replace and links to every guide in this set. A flat garage with a sound deck and a sensible fall is the easiest to price, so ask for the covering to be judged first.

Two garages on the same footprint can come back with quotes far apart. The reasons are plain ones, and most can be seen from the drive or from the loft hatch.

Size and shape

More roof means more covering, more boards if the deck is poor, and more days. Shape counts too. A bare rectangle with four straight edges goes quickly. A garage with a step in it, a chimney stack from the house wall, a rooflight or a lean-to section needs extra cutting and extra upstands, the short upturned lips of covering where the roof meets a vertical wall.

The deck under the felt

Underneath the felt sits the deck, the boarding or sheet material that carries the whole covering. After years of leaks that boarding can go soft, and anything laid on a soft surface will fail early. Press on it from the loft side if you can reach it, because spongy or darkened timber is a warning. Swapping a few boards is a small extra. Renewing most of the deck, or the joists under it, turns the job into something bigger.

Edges, drainage and the wall junction

The trims around the perimeter, the gutter or outlet, and the line where the garage meets the house or a boundary wall all demand patient work. A flashing at that wall dressed in lead takes longer to fit than a bead of sealant, but it keeps the junction dry for far longer.

The covering you pick

Felt, EPDM and GRP carry different prices, and so do corrugated sheets and tiles. The choice also fixes how many years the roof is likely to give, which the next section turns to.

The lower price on the day is not always the lower cost across twenty years. Lifespans are where the Less guide to flat roof costs (its table is dated March 2026) is most useful, and it lists these typical figures:

Those are ranges, never promises. Less adds that a well-laid felt roof may reach 20 years while a poorly laid one might give up in under 10, so who lays it moves the number as much as what is laid. GreenSpec puts EPDM at 20 to 30 years of expected service life, so the guides disagree with each other. Plan around the middle of the spread, not the top.

EPDM is synthetic rubber, supplied as a membrane that is usually cut from one big sheet, which leaves a small garage with hardly any joins to open. GRP means glass-reinforced plastic, brushed on wet and left to cure into a skin without seams. Felt is built from layers and sealed at every overlap. For a roof you want to forget about, fewer seams and a longer range often justify a higher starting price. For a garage you expect to knock down or convert soon, a shorter-lived covering can be the sensible pick.

Our guide to choosing between felt, EPDM, GRP and sheeting sets the options side by side for a garage, with the trade-offs for each, and the figures above give you the starting point for that comparison.

Plenty of older garages, including precast sectional types, wear corrugated sheets that may be asbestos cement. HSE's advice for a building dating from before 2000 is to presume asbestos is in it until a survey shows otherwise. That affects cost because the sheets must come off with care and travel to a site that takes them.

Checkatrade (table last updated April 2026) says removal of an asbestos cement garage roof typically runs between £950 and over £3,750. That spread concerns removal. The new covering is further work on top, and the written quote for both is one total.

On site, the condition of the sheets decides how the work runs. Under HSE's rules, lifting asbestos cement that stays whole is non-licensed work, so long as it is weathered but not substantially damaged. Once sheets are badly broken or crumble as they are lifted, the job becomes notifiable non-licensed work, and notice has to go to the enforcing authority before it begins. HSE also lists asbestos cement roofing as fragile, so nobody should stand on one, and that big pieces are lowered to the ground instead of being thrown down.

The waste has its own paperwork. The household exemption from a consignment note does not cover asbestos waste, so the contractor fills the note in as the producer. HSE's waste guidance calls for double wrapping, labels, and a lockable skip for the sheets.

If you suspect your own garage roof, leave it alone: no drilling, scrubbing or breaking. Our guide on how to tell if a garage roof is asbestos explains the clues.

A flat garage roof is never truly level. It is laid with a slope so rain runs to the gutter or outlet. BS 6229:2025, which replaced the 2018 edition in December 2025, retains a 1:80 minimum finished fall, and roofers commonly design nearer 1:40 to leave margin. Where an old roof ponds, the cure is often new firrings, tapered timbers fixed above the joists to create the slope. They add timber and labour, which is why a roof that holds puddles costs more to replace than one that drains.

Insulation and Part L

Approved Document L counts renewing the waterproof layer of a flat roof as renovation of a thermal element. Where over 50 per cent of that element's surface is renovated, upgrading the insulation may come into it, adding boards to a plain re-cover. Whether the rule reaches your garage can turn on how it joins the house and how you use it, so ask your building control body or your roofer to confirm before the price is fixed.

Planning and Building Regulations

Planning permission is seldom the issue when a worn covering is swapped for a similar one, although a listed building or an Article 4 direction can change that. Building control runs to separate thresholds. According to the Planning Portal, building control approval is rarely required where under 25 per cent of the building envelope and under 50 per cent of the roof is touched. Arun District Council, meanwhile, includes re-covering roofs among the alterations needing approval. Both statements can stand together, so put the question to the council's building control team, or to your roofer, before work starts.

VAT on roofing work is charged at 20 per cent. Checkatrade's flat roof replacement table is marked "(+VAT)" and its repair rates exclude VAT, so a £2,800 roof turns into £3,360 once tax goes on. With two quotes on the kitchen table, look for the VAT line in each, or a plain statement that tax is extra.

Labour is the other big piece. Checkatrade puts roofers at around £35 to £45 an hour or £280 to £360 a day. A garage re-cover can be short work, yet even a minimum day covers travel, setting up, clearing down and taking the waste away.

Access matters less on a garage than on a house, but it still matters. A garage with a drive beside it is usually reachable with ladders and a roof ladder. A garage down a shared alley, behind a terrace or hard against a boundary can mean carrying every roll and every bag of waste a long way by hand. Where scaffolding does stand on or over the pavement, section 169 of the Highways Act 1980 requires the highway authority's consent, which needs notice. West Sussex County Council wants at least 10 working days between application and erection and charges £266 for one month. Checkatrade's October 2026 scaffolding table gives around £1,000 a month for a detached bungalow, so raise scaffolding early if the job needs it.

A survey of a garage ends with photographs of the roof, a verdict on mending versus renewing, and a single written total. We think our prices are good and fair, and our guide to repairing or replacing a garage roof shows how that verdict gets reached.