Farm sheds, garages and the asbestos question
Outbuilding roofs are easy to ignore, and the oldest sheet coverings need a careful method before they are touched.
A farming and mining village collects outbuildings, and few of them get a second thought. Garages, workshops, lean-to stores and sheds carry sheet coverings that have often outlived the people who put them up. They get little attention, and when they let go the contents get wet before the house does.
Old corrugated cement sheet may contain asbestos. Whether a particular sheet does is a matter for identification, not guesswork, so until a roof has been identified it is treated as if it might. Under HSE guidance, taking asbestos cement sheeting off with care is non-licensed work as long as the sheets are lifted intact. Heavy breakage, which means a lot of dust and debris, moves the job into notifiable non-licensed work. That is why the method matters more than the speed: how the sheets are fixed, what state they are in and where they will be stacked all shape the plan. The rules are laid out in the HSE guidance for anyone who wants to read them.
With the covering identified, the choice is between mending, covering over and stripping. A sound sheet roof with a few failed fixings can often be mended and left in place. A roof that is cracked across many sheets, or that has rotted purlins underneath, is better stripped and re-laid, because a new covering over rotten timber is a short-term answer. On a garage the new roof may be flat or pitched, and the material depends on the span, the falls and the budget. A flat garage roof needs a fall towards the gutter so water does not pond, and that fall is set out before any membrane goes down.
The detail on materials, fall and costs sits on our garage roof replacement page. The table below shows national ranges only, taken from a MyBuilder guide of 2026; your own fixed quote is written after the survey.
National ranges for garage roofs and asbestos removal (MyBuilder, 2026)
| Job | Typical range |
|---|---|
| One-car garage with a flat roof | £700 to £1,000 |
| Two-car garage with a flat roof | £900 to £1,400 |
| Garage with a pitched roof | £2,500 to £4,500 |
| Asbestos removal, averaged across jobs | About £2,000 |



