Garage & outbuilding roofs
In short
Garage roofs are usually the oldest and least maintained covering on a property, and they come in three flavours: tired felt, corrugated cement sheet that may contain asbestos, and corrugated steel or fibre. The right answer depends on which one you have and on what the structure will take.
Also called: Garage roof replacement · Garage roof leaking · Asbestos garage roof · Outbuilding roof
Signs you need this
- Water dripping into the garage or staining on stored items
- Felt that has blistered, split or gone chalky
- Grey corrugated cement sheets — likely asbestos if pre-1980s
- Rusted-through corrugated steel sheeting
- A soft or sagging deck
- Rotten fascia, bargeboard or gutter around the garage
A garage roof gets almost no attention until it fails, which is why so many of them are twenty years past their covering's life. The good news is that they are usually cheap to put right compared with anything on the house, and they are a straightforward job when the structure underneath is sound.
Felted flat garage roofs are the commonest and the simplest. Strip back to the deck, replace whatever boards have gone soft, form proper falls, and re-cover — usually in EPDM, which suits a plain rectangle perfectly and goes down in a day. The important part is the deck: a garage roof that has been leaking for years often has more rot than the owner expects, and covering over it wastes the covering.
Corrugated cement sheet is the one to be careful with. If it went on before the mid-1980s it very probably contains asbestos, and that changes how it is handled entirely. Work on it falls under the Control of Asbestos Regulations 2012. Asbestos cement is usually non-licensed work — a trained contractor can remove it without an HSE licence — but it must not be broken up, power-cut, or dropped off the roof, and it has to go to a licensed waste site with a consignment note. Sheets get taken down whole, wrapped and disposed of properly.
The tell for asbestos cement is a grey, slightly fibrous corrugated sheet, often with a weathered, roughened surface and sometimes with moss established in the corrugations. Modern fibre cement looks similar and is not asbestos, so age is the better guide than appearance — and where there is genuine doubt it gets sampled and tested rather than guessed at. It is not dangerous to leave in place if it is sound and undamaged; the risk comes from disturbing it.
Pitched garage roofs — tiled, or corrugated steel — are their own thing. A tiled garage roof is a small version of a house roof and gets treated the same way. Corrugated steel or bitumen sheet is quick and cheap and appropriate for a workshop or store, less so for anything you care about the look of.
The structural question is worth asking before the covering is chosen. Garages are lightly built, and some of the older prefabricated concrete ones in particular have limited capacity. Putting a heavier covering on than the frame was designed for is a real mistake, and it is why a tiled finish is not always available on a structure that currently carries a sheet.
What the job covers
- Strip back to the deck and full inspection of the structure
- Rotten deck boards and timbers replaced
- Proper falls formed before any new covering goes on
- EPDM, GRP or felt specified to suit the roof and the budget
- Asbestos cement handled under the 2012 Regulations and disposed of correctly
- Guttering and rainwater discharge sorted at the same time
What it costs
We don't publish a price for this yet, because a number pulled out of the air is worse than no number at all — your roofer has to honour it. On roofing it would also be close to meaningless: access is often the biggest single factor, and it varies enormously house to house. You'll get a firm price for your actual job when they ring you back, before any work starts. The quote itself is free and there's no obligation either way.
Common questions
Does my garage roof contain asbestos?
If it is grey corrugated cement sheet and went on before the mid-1980s, very probably. Modern fibre cement looks similar and does not. Where it matters — and it matters as soon as anybody is going to disturb it — the answer is a sample and a test, not a guess from the ground.
Is it dangerous to leave asbestos sheeting alone?
Generally not. Asbestos cement in sound, undamaged condition is stable and the fibres stay bound in the cement. The risk comes from disturbing it — breaking it, cutting it with a power tool, or dropping it. If it is intact and you are not working on it, leaving it in place is a legitimate decision.
Can I put tiles on my flat garage roof?
Only if the structure will take the weight and the pitch can be created, which on most flat-roofed garages means building a new pitched frame over the top. That is a real job rather than a covering change. On a lightly-built or prefabricated garage the structural answer may simply be no.
Is it worth doing properly on a garage?
Yes, because the difference in cost between a proper job and a cheap one on a roof this size is small, and the difference in outcome is fifteen years. Stripping to the deck, sorting the falls and laying EPDM on a standard garage is not a large job — but re-covering over a rotten deck is money you spend again in three years.
Need this doing in Macclesfield?
Tell us the job and it goes straight to our local roofer — one call back, usually the same day. Free quote, no obligation.