Roof removal is priced from four things and none of them is the asbestos itself: the number and type of sheets, the access method, the disposal weight and route, and whether a replacement covering is included. Get those four onto every quote and the numbers become comparable. Leave them off and the cheapest quote is usually the one that has assumed somebody else is paying for the waste.
Sheets and structure
Count the sheets, note the pitch, and say whether the purlins and the frame are staying. A roof coming off a sound steel frame is a different job from one where the timbers have rotted under a leaking lap. Contractors price the strip from the sheet count and the making good from what is underneath, so telling them both up front avoids the variation afterwards.
Access
Asbestos cement is a fragile material and falls through fragile roofs are a long standing cause of construction deaths, so access is a real line. A tower for a single garage, a scaffold with edge protection and crawling boards for anything larger, a mobile platform where the ground allows. A quote with no access method named has not priced the largest part of itself.
Disposal
Cement sheet is dense and disposal is charged by weight at a permitted site, so on a large roof the waste can rival the labour. Ask for the disposal measure, the route and who holds the consignment note. This is where two quotes for the same roof most often differ by a factor rather than by a margin.
Replacement
A stripped roof is an open building. Removal and re-roofing are usually separate trades sharing one set of access equipment, and arranging them separately means paying for that equipment twice. Ask each contractor whether they replace, and if not who does and when the building is covered.
Questions people ask about asbestos roof removal cost
Is roof removal licensable work?
Work on asbestos cement is normally non-licensed. If the survey finds insulating board or sprayed coating rather than cement, the job becomes licensable and the price changes completely.
Can the sheets be left and covered over?
Overroofing a sound asbestos cement roof leaves the material in place and undisturbed, and it is often the cheaper answer. It has to be recorded so the next person to open the roof knows.
Why do quotes differ so much?
Access and disposal, almost always. Match those two lines across quotes and the range narrows sharply.