How long does a new garage flat roof last?

It depends almost entirely on the covering. A budget mineral felt might give you 10 to 15 years on a garage. A properly torched three-layer felt system should manage 20 or more. EPDM rubber, laid as a single sheet with no joints, is generally expected to run 25 to 40 years, and fibreglass sits in a similar bracket if the base is rigid enough for it. On a garage the structure underneath rarely limits the life - it is the covering and the edge details that give out first.

Can you put a new layer of felt over the old garage roof covering?

Sometimes, and it is nearly always the wrong call. An overlay only works if the existing covering is dry, flat and well stuck down, and the roof that needs recovering is rarely any of those things. Trapped moisture under the new layer blisters it in the first hot summer, and you have paid twice. The honest exception is a sound roof being upgraded early for a garden room conversion. For a roof that is already leaking, strip it.

How can I tell if my garage roof is asbestos cement?

Age and appearance are the clues. Grey corrugated sheets on a garage or prefab built before the mid-1980s should be treated as asbestos cement until tested - the material was standard on concrete sectional garages for decades. It is dull grey, slightly rough, often mottled with lichen, and the sheets are fixed with bolts or screws through the ridges. Do not drill, break or pressure-wash it. A sample test costs little and settles the question before anyone touches the roof.

Do I need permission to replace a garage roof in Weston-super-Mare?

For a like-for-like recovering, no - replacing the covering on an existing garage is repair, not development. Where it gets more involved is if you raise the roof, change its shape, or the garage sits in one of the town's conservation areas, where North Somerset Council may take an interest in visible changes. Detached garages are also subject to outbuilding rules on height if you rebuild rather than recover. A straight strip-and-recover on an existing footprint needs nobody's blessing.

Replacing A Garage Flat Roof In Weston-super-Mare: Options, Costs And The Asbestos Question

There is a particular sound a failed garage roof makes in Weston when it rains - a flat drip onto whatever you were foolish enough to store directly under the low point. Every street from Milton down to Uphill has a garage making it right now.

Garages get the worst roofs on the property and the least attention afterwards. The covering was usually the cheapest option available in the year the garage went up, laid over the thinnest deck that would hold a man’s weight, and it has been quietly cooking, soaking and refreezing ever since. Nobody insulates a garage roof, nobody inspects one, and the first anyone hears of a problem is a wet freezer motor.

The good news is that a garage is the cheapest flat roof you will ever replace, and small enough that doing it properly does not hurt. This is how the job actually breaks down.

Why the garage roof always goes first

The garage roof fails before the house roof for reasons that were designed in. Most were built with a single or two-layer mineral felt - a covering with a realistic life of 10 to 15 years - and many are now on their third or fourth decade of the same material, patched rather than replaced each time it opened up.

They also get no help from below. A house roof sits over a heated building; a garage roof freezes solid in January and hits 60 degrees under a July sun with nothing underneath to even out the swings. That thermal cycling is what cracks bitumen, and an uninsulated deck gives the covering the full dose of it. Add falls that were marginal on day one and have sagged since, and you have standing water working at every crack the sun opened.

None of this means the garage itself is finished. The brickwork and doors of a 1970s garage in Ashcombe or Worle are usually good for another fifty years. It is a job for a felt and torch-on specialist or a rubber roofer, not a demolition crew.

Patch, overlay or strip: getting the decision right

The repair-or-replace question is simpler on a garage than on a house extension, because the stakes are lower and the arithmetic is blunter.

A patch makes sense for one puncture on a covering that is otherwise sound and under ten years old - a dropped ladder, a fox, a botched aerial fixing. It does not make sense on felt that has crazed all over, because the patch outlives the roof around it and you are back up there within the year.

An overlay - new covering over the old - is the option that tempts people because it skips the strip-out cost. The problem is moisture. Old felt that has leaked holds water in its layers and in the deck below, and sealing a new sheet over damp material traps it. The sun then boils that moisture into vapour with nowhere to go, and the new covering blisters off. We overlay so rarely in this town it is barely worth pricing.

A strip back to the deck is the honest answer for most garage roofs that are actually leaking, and because a garage is small, low and usually reachable without scaffold, stripping it costs a fraction of what the same decision costs on a house.

Felt, EPDM or fibreglass on a garage

The three coverings that dominate flat roofing all work on garages, but the balance between them shifts when the building is unheated and nobody walks on the roof.

Torch-on felt is the budget-sensible choice it has always been, provided it is a proper polyester-reinforced system and not the bargain mineral roll from a shed. On a garage its main weakness - a shorter life than the alternatives - matters less, because there is no ceiling below to ruin when it eventually goes, and recovering is cheap to repeat.

EPDM rubber has become the default for garage roofs, and for one very good reason: a single garage can usually be covered in one sheet with not a single joint anywhere on the roof. No joints means no seams to fail, which removes the way most garage roofs die. It also shrugs off the thermal cycling that kills bitumen on an uninsulated deck.

GRP fibreglass gives the hardest-wearing finish of the three but it wants a rigid, dry, well-fixed deck to cure against, and garage decks are the least rigid you will meet. On a springy 1960s deck it can crack along the board lines. It is the right choice on a garage only after the deck has been replaced - which, as it happens, is often part of the job anyway.

The deck underneath decides half the price

Quote a garage roof from the pavement and you are quoting half the job. What the covering sits on is invisible until the strip, and it is where garage roofs hide their surprises.

Plenty of Weston garages were decked in chipboard, which holds up only as long as it stays bone dry. One winter of a slow leak turns it to something like damp biscuit, and no covering can be fixed to that. Others have 1960s softwood boards that are sound in the middle and rotten at the edges where the gutter overflowed for a decade.

A decent roofer prices the recover and gives you a rate for deck replacement per board or per square metre, agreed before the strip, so the mid-job phone call is a number you have already seen. New decks go down in 18mm OSB3, which is the modern standard - flat, rigid, and happy under any of the three coverings. If you are hoping for fibreglass, budget on the assumption the deck is coming up.

The asbestos cement question

A large number of Weston garages - particularly the concrete sectional type sold through the 1960s and 70s, and plenty of brick ones besides - carry corrugated asbestos cement sheets rather than felt. If your garage roof is grey, corrugated and older than you are, this section is for you.

The first thing to say is: do not panic, and do not reach for the pressure washer. Asbestos cement in good condition is low risk precisely because the fibres are locked in the cement. It becomes a problem when it is broken, drilled, cleaned aggressively or crumbling with age - which is why the Health and Safety Executive’s asbestos guidance is emphatic about leaving sound sheets alone and never working on them dry.

When the sheets do need to come off, a homeowner can legally remove asbestos cement from their own garage, but the practical answer is usually to have it done by someone insured for it, sheeted, unbroken, and double-wrapped. Disposal is the part people trip on: it cannot go in the wheelie bin or a standard skip, and North Somerset Council’s waste service sets out the arrangements for dealing with it locally. Factor removal and disposal into the budget from the start - it is the difference between the quotes more often than the new covering is.

What a garage roof replacement costs here

Because garages come in standard sizes, prices cluster more tightly than for any other flat roof. As a guide from the jobs we price around Weston, Worle and the villages: a straight strip and recover on a single garage in torch-on felt generally lands somewhere between £900 and £1,400. The same roof in EPDM runs £1,100 to £1,700. Fibreglass, where the deck supports it, sits a step above that again.

Double garages do not simply double the figure - the access, waste and edge trims are shared - so expect perhaps 60 to 80 per cent on top rather than 100. Deck replacement adds a few hundred pounds if the whole thing comes up. Asbestos cement removal and disposal on a single garage is commonly a £400 to £800 line item before the new roof goes on.

One thing worth knowing: most of our garage enquiries turn out to cost less than the customer had braced for. The garage is the flat roof where the numbers are small enough to do the job properly without wincing - which is exactly why skimping on it makes so little sense.

What a proper job includes, and what to ask

A garage roof done right is not just a covering. The falls should be checked and corrected with firring strips if the deck has sagged into a bird bath. The edges want proper trims - drip trims into the gutter, raised edges elsewhere - not felt folded over the fascia and nailed. The gutter itself should be refixed at the correct fall while everything is accessible, because a garage gutter that overflows against the brickwork is how the next deck edge rots.

If the garage is attached to the house, the junction against the house wall matters more than the whole rest of the roof - it wants a chased-in flashing, not a smear of sealant. And if you are ever likely to convert the garage or put a living roof on top of it, say so at quote stage: the deck spec and covering choice change, and it costs far less to allow for it now than to redo it later.

Permission, for the avoidance of doubt, is rarely an issue - recovering an existing garage roof is repair, though rebuilding one brings the Planning Portal’s outbuilding rules on height and siting into play, and conservation areas add their own layer.

Ask any roofer quoting yours three things: what happens if the deck is bad, exactly how the edges and the house junction will be finished, and where the waste - especially any asbestos - is going. The answers tell you nearly everything about the job you will get.

If yours has started dripping onto the freezer, get a free quote on your garage roof - we cover Weston-super-Mare and everywhere around it.