Asbestos roof removal: what to expect
Asbestos cement was widely used for garage, shed and workshop roofs in the post-war decades. Left alone and in fair condition it poses little day-to-day risk, but it must not be broken, drilled, sanded or pressure-washed, and it cannot go in a household skip. Removal is a controlled process with defined steps.
Most asbestos roofs on garages and outbuildings are corrugated asbestos-cement sheets. Where the material is suitable, they are dampened, unbolted and lifted whole without breaking, wrapped, and taken away by a licensed waste carrier, with a consignment note as proof. A replacement covering can then go on straight away.
Confirming what the roof is made of
Corrugated grey sheets on an older garage are often asbestos cement, but appearance is not proof. Newer fibre-cement sheets look similar. If there is any doubt, a sample can be tested before work is planned. The type matters because asbestos cement is usually handled as non-licensed work, while sprayed coatings, lagging and insulating board require a licensed asbestos contractor. A roofer should identify which situation applies before quoting and say plainly if the job needs a specialist.
Why the sheets are removed whole
Fibres are released mainly when the material is broken, cut or abraded. The removal method is therefore built around keeping each sheet intact. Surfaces are dampened to suppress dust, fixings are released rather than forcing the sheets, and each sheet is lowered by hand instead of being dropped. Rusted bolts are the usual complication; they need patient work so the sheet around them does not crack. Previous DIY damage, over-boarding or broken ridge pieces also change the approach.
Protection on site
The working area is kept clear of people who are not involved, and the ground below is protected so fragments do not reach soil, paths or drains. Operatives wear respiratory protection and disposable overalls suitable for the task. You will be asked to keep windows nearby closed, move vehicles and keep children and pets away while the roof is being stripped. A tidy, controlled site is a good sign; sheets being snapped and thrown into an open skip is not.
Wrapping, transport and disposal
Removed sheets are double-wrapped in heavy polythene, sealed and labelled as asbestos waste. Household recycling centres generally will not accept this material from the public, so it goes to a permitted facility through a licensed hazardous-waste carrier. You should receive a waste consignment note showing where the material went. Keep it: it is your record that the roof was disposed of lawfully, and a buyer’s surveyor may ask about it later.
What goes on afterwards
Once the sheets are off, the supporting structure is checked. The replacement options described on this site are box-profile steel sheeting, insulated or single-skin, or an EPDM rubber membrane over a new deck, which suits garages being turned into workshops or home offices. Quoting removal and replacement together keeps the scope clear and means the building is not left open for long.
Planning the job
Access for a skip or vehicle, the size of the roof, the number of sheets and how the structure below is used all affect the plan. Clear the garage or outbuilding before the day, or at least cover contents with sheeting. Tell your neighbours if the roof sits on a shared boundary. If the building has electrics or lighting under the roof, those should be made safe first. Photographs of the whole roof and its fixings help a contractor judge the job before visiting.
What a written quote should include
Ask for the identification of the material, the method statement, protection measures, removal, wrapping, transport, disposal paperwork, and the replacement roof as separate items. The quote should also say what happens if the timber frame proves unsound once the sheets are lifted. Avoid any offer to break the sheets down to fit a general skip or to overlay the old roof without addressing its condition.
Leaving an asbestos roof in place
Removal is not always urgent. An intact roof that is not being disturbed can be monitored, and planned work can be timed to suit you. The case for removal grows when sheets are cracked, fixings are failing, the roof leaks, or you want to convert, extend or demolish the building. Never attempt to clean moss off an asbestos roof with a pressure washer or wire brush; that is exactly the kind of damage the process is designed to avoid.
FAQs
Suitable asbestos-cement sheets are usually non-licensed work under the Control of Asbestos Regulations. Other asbestos materials need a licensed contractor.
No. The waste must be wrapped, labelled and taken by a licensed carrier to a permitted facility, with a consignment note.
Often, yes. Removal and a box-profile steel or EPDM replacement can be quoted and planned together.
An intact roof that is not disturbed can usually be monitored, but it should not be drilled, broken or pressure-washed.
Related reading
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