The main choices
Box profile steel sheeting is the usual pitched-roof choice: light, long lasting and quick to fit. Cement-free fibre sheets keep the look of the original corrugated roof but are heavier and can be brittle underfoot. Bitumen corrugated sheets are cheap and quiet but have a shorter life. For a flat or low-pitched garage a rubber EPDM or GRP system is more usual.
If the garage is used as a workshop or for storage, insulated or anti-condensation sheeting stops the drips that bare steel can cause on cold mornings.
What to check before work starts
Look at the timbers. Old garage rafters and purlins are often thin, and cement sheets are heavier than steel, so the structure usually has no trouble with a new steel roof, but rotten timbers need replacing. Make sure the quote says who repairs them.
Check the fascia, gutters and downpipes. A new roof without new guttering often leaves the same damp problem you started with.
Planning and neighbours
A like-for-like roof on an existing garage normally does not need planning permission, but raising the roof or changing its footprint can. If the garage is part of a terrace or lane, tell the neighbours before the scaffold goes up, especially if the roof is shared.
Thinking about solar
If you might add solar panels, say so now. A roof with the right pitch, orientation and fixings is easier to add to than one that has to be reworked later. Our solar page explains what is involved.
Common questions
How long will a new steel garage roof last?
Well-fitted pre-coated steel sheeting commonly lasts decades. Colour fades before the structure fails, and the warranty depends on the product and the fitter.
Will a steel roof be noisy in the rain?
Bare steel can be. A backed or insulated sheet is much quieter and also reduces condensation.
Can I keep my existing gutters?
Often not. Old gutters tend to be cast, cracked or sagging, and replacing them while the roof is off is cheap compared with doing it later.