What removal involves
Cement sheets are bonded, which means the fibres are locked into the cement. The danger comes when the sheets are broken, drilled, scrubbed or pressure washed. A careful removal keeps sheets whole, wets them where needed, and avoids breaking anything on the way down.
Sheets are lowered or carried down by hand rather than thrown, wrapped in heavy-duty polythene, labelled as asbestos waste and loaded for a licensed tip.
When removal only makes sense
Removal on its own is common when a garage is being demolished, when the building is being converted into a room, or when the owner has a roofer in mind and wants the asbestos dealt with first.
If the garage is staying and it needs a roof, it is usually better to combine the two jobs so the building is open to the weather for as short a time as possible.
Waste and paperwork
Asbestos waste has to go to a site licensed to accept it, carried by a registered waste carrier, with a consignment or transfer note. Ask for a copy. In Greater Manchester most household waste sites do not accept asbestos, so the roof is not something to take to the tip yourself.
What it costs
For a single garage, UK firms commonly quote in the region of £600 to £1,000 for removal and disposal, and more for a double garage. Large or awkward access, extra outbuildings and the need for scaffold all move the price.
Common questions
Can I leave the garage open once the roof is off?
It is not a good idea. Rain will damage the contents and timbers, so most owners arrange a replacement roof straight away.
Do I need to be at home?
Usually not for the whole job, but someone should be reachable for access, and you should keep children and pets away from the working area.
Is a survey needed before removal?
Not for a visibly cement-sheet garage roof, which is normally treated as asbestos. A sample can be taken if there is genuine doubt.