The short answer
HSE's advice is to treat any building put up or refurbished before 2000 as containing asbestos until shown otherwise. A corrugated, grey, fibre-cement garage roof from that era very probably does, though looks alone cannot prove it. Analysis of a sample, taken by a competent person, gives a definite answer. Until then, do not drill, cut, scrub or break the sheets.
The age rule and what it means
HSE's guidance is blunt and useful: where the building predates the year 2000, in construction or refurbishment, presume asbestos is there. For a garage that matters in two ways. The structure may date from before 2000, and the roof may have been renewed at a later date with something quite different. A 1960s garage with a roof re-sheeted in 2010 is not the same as one with its original sheets, and a 1990s garage with a replacement roof from a couple of decades ago needs checking, not assuming.
Find out what you can. The deeds, the valuation report from your purchase, the building's planning history and any neighbour who remembers the work are all worth asking. Estate garages built in blocks, often as a row at the back of a street or a courtyard, tend to share one roof design and one age. Our page on garage block roofs deals with those shared structures.
The age rule is a reason for caution, not a diagnosis. It tells you to behave carefully until the material is identified.
What an asbestos cement garage roof tends to look like
Garage roofs of the 1950s, 1960s and 1970s were very often built from large corrugated sheets of asbestos cement, laid in overlapping courses on timber or steel purlins. They are typically grey, sometimes weathered to a mottled green or black with moss and lichen, and they have a rough, slightly fibrous surface where the edges have worn.
Other features support the suspicion. The sheets are brittle and crack across a corrugation if walked on. They sit on a low pitch, with a ridge made of angled cement pieces bolted on. Fixings are often hook bolts or galvanised screws with small caps. Soffits and eaves boards can be asbestos insulating board as well, and HSE lists external soffits among the places AIB turns up.
None of this proves the material. Modern fibre-cement sheets without asbestos look nearly identical, and HSE says it is hard to tell AIB from non-asbestos equivalents. Never scrape, scratch or take a piece off to look. The sheets are the one thing you should leave alone until you know.
Testing, and what it costs
A sample is the only reliable method. A competent person takes a small piece in a way that does not scatter fibres, seals it, and sends it to a laboratory for analysis. Some sellers and surveyors arrange this; so can a roofer. We are happy to talk through the process on a survey, and our page on asbestos test costs goes into the options.
MyBuilder's asbestos removal guide, updated 21 August 2026, puts a basic survey at around £50 upward, and a fuller survey at £200 to £245. Those are typical national figures, and what you pay depends on who takes the sample and where the garage is.
A negative result is just as useful as a positive one. It lets you replace the roof as an ordinary job, or leave it alone if it is sound. A positive result does not mean panic. HSE places careful, unbroken removal of cement roof sheeting in the non-licensed category, and an intact, undamaged roof that is left alone is not an emergency in itself.
What to do, and what not to do, while you wait
Treat any suspect sheet as if it were asbestos until a result says otherwise. Do not drill, saw, sand or wire-brush the surface. Do not pressure wash it, because that blasts weathered surface fibres and sends contaminated water into the ground. Do not step on it, and keep children and pets clear of any area with broken sheets.
If a sheet is already cracked or fallen, do not sweep up the pieces. Keep people out, cover the area with polythene if you can do so without disturbing it, and ask for advice. Our guide to the asbestos licence question sets out who can lawfully do which kind of work, which helps when you are comparing contractors. We check the material first and pass licensed work to a licensed firm.
Where a roof is sound and intact, the sensible plan is often to monitor it and leave it, then replace it when it reaches the end of its life. Where it has been damaged, there is a stronger case for action. We will tell you which applies, and we put the lighter option first whenever it genuinely solves the problem.
If it is asbestos: what happens next
The next step is a decision about the roof. You can leave it if it is sound and nothing is disturbing it, encapsulate it in some cases, or remove it and fit a new covering. Removal needs a careful method, correct disposal and paperwork. For asbestos leaving a household, the contractor acts as waste producer and completes the consignment note, and the sheets are taken to a site able to receive them.
MyBuilder gives a single garage roof removal range of £350 to £1,295 and a double garage £650 to £1,800, with the cost of a replacement covering extra. Our garage roof cost page shows how those removal figures sit alongside the price of new roofs. Those are national typical figures, not our prices. Our survey leads to a written quote, with pictures from your garage, and you should ask any firm whether its figure includes VAT.
Buying or selling is another reason to know early. A buyer's solicitor may ask, and the answer shapes the sale price. If you are ready to find out, start from our garage roof replacement page and arrange a survey.