The short answer
On site, replacing a single garage roof is a short job compared with a house. The calendar stretches because of what comes around it: the survey, any scaffold licence, weather, a rotten deck found underneath, and the extra steps when the sheets are asbestos cement. A reliable programme comes from the survey, and we give it before work starts.
The roof itself goes on quickly. Most of the waiting is for things that happen before the first tool comes out of the van.
What decides the length of the job
Four things shape a garage roof timetable: how big and how complicated the roof is, the covering going on, the state of what lies underneath, and the weather. A small flat roof in felt or a membrane is a modest task. A larger double garage with a pitched roof, new battens and a ridge takes longer, and the roof loses days if rain stops the work at the wrong moment.
Why does the deck matter to the schedule?
Nobody knows what is under the old covering until it is lifted. A dry, sound deck means the new layers go straight on. A soft deck or damp joists mean cutting out boards, treating or replacing timber and drying the area before the roof can be closed in. That is why the written price and the programme both follow the survey, where we lift a section where it is safe and show you photos of what sits there.
You can help by clearing the garage floor below the roof and moving vehicles out of the way of falling debris. Our guide on repairing or replacing a garage roof may also shorten things, since a repair is a far quicker visit.
Before the work starts: surveys, licences and paperwork
A good deal of the elapsed time sits before the roof is touched. The survey comes first, then your acceptance of the single written price, then materials ordered and a date agreed. Customers who sign at home after a survey also get a 14-day cancellation right on that contract, and the date is arranged with that period in mind.
Does a garage roof job need scaffold on the road?
Not always. Where the garage sits on a drive, a tower or edge protection on private land is enough. If scaffolding has to occupy part of the public footway, a licence under section 169 of the Highways Act is the first step. Somerset Council holds that role for Taunton, and it gives permits to accredited contractors alone, which makes the appointed contractor the applicant. At least 10 working days' notice is requested. The fee is £124.60 per 28-day period (Somerset Council, April 2026).
If a change of shape is planned, the council's planners may need to see it first. Somerset Building Control quotes 10 working days before you hear back on a full plans application, and normally 5 weeks to a decision. Our answer on garage roof planning permission explains when that applies.
Extra steps when the sheets are asbestos cement
An asbestos cement roof adds stages that a felt or metal roof does not have. The material is identified first, because HSE's advice for a building from before 2000 is to assume asbestos is present. A method is then chosen. Lifting asbestos cement sheets off carefully and whole falls under non-licensed work. Sheets that end up badly broken turn the job into notifiable non-licensed work, which carries more paperwork.
Why does asbestos waste slow the job?
Because it cannot be skipped or thrown into the household stream. The sheets are double-wrapped and labelled, as HSE's EM9 guidance puts it, and it travels under a hazardous waste consignment note, carried by a firm with upper-tier carrier registration. An ordinary skip will not do.
The new roof cannot start until the old sheets are off and the purlins have been checked, so planning the removal, the wrapped load and the collection date takes real time. Read our page on asbestos garage roof removal for the full sequence, and ask for the whole timetable in writing before you agree to start.
Weather, access and a realistic start date
Roofing is outdoor work, so weather has the last word. Felt and membrane need a dry deck and a dry spell to bond, and wind makes handling large sheets unsafe. A job booked for a still week can slip a few days, and we would rather tell you than leave the roof exposed. Each section is opened only as far as it can be covered again, with temporary protection over any layer left unfinished.
Is winter a bad time for a garage roof?
Not necessarily, with sensible choices. Some coverings tolerate cold better than others, and the roofer picks the system, and the order of the stages, to suit the forecast. Rain on a bare deck is the enemy. Out on the Somerset Levels or up in the Quantocks, wind and driving rain also affect when sheeting can be lifted into place safely.
Clear access matters too: a drive free of cars, room for materials, and a path for waste. Tell us at the survey about narrow lanes, shared access or a garage tucked behind the house, and we plan the delivery. The garage and asbestos roofs page shows the work we cover.
More on garage roof timing
Must someone stay home during the garage roof work?
Not throughout, though we would like a contact reachable at the start and finish. We walk you through the plan beforehand, agree where materials and waste go, and show you what was done at the end. If the garage is attached, the house may need protecting from dust and noise.
Can a leaking garage roof wait for the new roof date?
A leak should not be left to soak the deck, because wet timber turns a small job into a big one. We can make the roof safe first with a temporary repair, then book the replacement. Tell us what the leak is doing when you call, and keep photos of any stains.
The full picture: Garage and asbestos roof replacement in Taunton · More short answers