Asbestos Garage Roofs: How to Identify Them and What Removal Costs

Grey corrugated roofing on a garage, shed or outbuilding is one of the most common ways people come across asbestos directly – not hidden in a wall cavity, but sitting in plain sight at the bottom of the garden. Two questions almost always follow: is it actually asbestos, and what does dealing with it actually involve?

How to tell if a garage roof is asbestos cement

The single best clue is age. If the garage, shed or outbuilding was put up, or last re-roofed, before 2000, the roof sheets may well be asbestos cement – see our timeline of when asbestos was banned in the UK for why that date matters.

Visually, asbestos cement sheets are typically grey or off-white, corrugated, and have a matte, slightly fibrous-looking surface rather than the smoother, more uniform finish of modern fibre-cement or metal profiled sheets. They’re often sold and referred to in the trade as “Big Six” sheets, after the corrugation profile, though that profile is also made in non-asbestos fibre cement today, so the name alone doesn’t confirm anything. Sheets are sometimes painted over, which can hide the texture that would otherwise be a useful clue.

None of this adds up to certainty. The only way to know for sure is to have the material tested or surveyed – appearance and age narrow it down, but they don’t confirm it.

Why this material is usually lower risk – if it’s left alone

Asbestos cement is a bonded, non-friable material: the asbestos fibres are tightly locked into the cement itself, rather than sitting loose the way they do in old lagging or sprayed insulation. Left undisturbed and in reasonable condition, that generally makes it lower risk than the more hazardous materials we cover in our room-by-room guide to what asbestos looks like.

That changes the moment the sheets are disturbed. Cracked, crumbling or deteriorating sheets release fibres on their own. So does cutting, drilling or grinding them. And so, very commonly, does jet-washing or pressure-washing a mossy old garage roof to clean it up – a genuinely popular DIY weekend job that’s one of the most effective ways to release fibres from a material that was otherwise sitting there safely.

The legal side: usually non-licensable, but that’s not the same as DIY-friendly

As we explain in our guide to what UK law actually says about removing asbestos yourself, the Control of Asbestos Regulations 2012 split work into licensable and non-licensable categories. Asbestos cement – exactly the kind of material a garage or shed roof is usually made from – is one of the standard examples of work that can be treated as non-licensable, provided a proper risk assessment concludes exposure will be low and sporadic, and the right controls are followed.

“Non-licensable” doesn’t mean “no rules”, and it doesn’t make it a straightforward DIY job. Sheets still need to be removed whole wherever possible, without breaking, dropping or cutting them, handled with the right protective equipment, and taken away by a registered waste carrier to a site permitted to accept asbestos waste – a normal household tip or skip won’t take it, and driving it there yourself without the right registration is an offence. Getting all of that right, safely and legally, is exactly what a licensed contractor does as routine.

What actually drives the removal cost

There’s no single number that means much here, because garage and outbuilding roofs vary so widely. What genuinely moves the price:

• Roof size and sheet count – a single small garage is a different job from a larger outbuilding or a run of several sheds.
• Access – a straightforward single-storey garage is quicker and safer to work on than a roof that needs scaffolding or extra access equipment.
• Condition – already-cracked or broken sheets need more careful handling and bagging than sheets that can be lifted off whole.
• Disposal – asbestos waste has to go to a permitted site via a registered carrier, which costs more than ordinary construction waste.
• Whether new roofing goes on afterwards – replacing the roof at the same time as removal is a different job and quote to removal alone.

Because those factors can move the price by a large multiple from one garage to the next, we’d rather not put a ballpark figure here that could be genuinely misleading either way. The only way to get a real number is to have the actual roof assessed.

What to do next

If you think you’ve got an asbestos cement roof, the safest move is simple: leave it alone. Don’t drill it, cut it, jet-wash it, or start pulling sheets off yourself, and it’s very likely doing you no harm at all sitting exactly where it is. When you’re ready to deal with it – or just want to know for certain what you’re looking at – get in touch for a free, no-obligation quote and we’ll tell you plainly what’s involved.