Garage roof timescale
How long does it take to replace a garage roof?
The short answer
That depends on the size of the garage, the new covering and whatever is found under the old one, so we set the programme out in the quote that follows the survey. Asbestos sheeting, rotten decking, wet weather and a scaffold licence for the road each add time, and the survey shows which of them apply.
What controls the length of a garage re-roof, which steps come before the first day on site, and what can stretch the job.
The size and the covering set the baseline
A single garage covered in one rolled membrane is a small job. A double garage in felt, or a long block with several bays, is a bigger one. Roofs with rooflights, upstands, awkward corners and a parapet take longer than a plain rectangle, because every detail has to be dressed properly.
The covering matters too. Felt goes on in layers, and each layer is sealed before the next. EPDM is stuck to a prepared deck. Box-profile sheets are screwed to purlins. Each needs its own skills, materials and conditions. Our comparison of felt and box-profile sheets shows how they differ in the work as well as the result.
A promise of so many days before anyone has looked at the roof is only a guess. After the survey, the written quote pins down the work, and the programme grows out of it. Small garages can look simple from the road and turn out otherwise, so we would rather measure first and talk about timing second. A pitched roof also depends on the timbers beneath: one that needs new battens or purlins before the covering can go on will take longer than one where the structure is sound.
What lies under the old roof
A flat garage roof is not fully known until the covering comes off. Soft boards, rotten joist ends and wet insulation are common finds under an old felt roof, and each one means extra work: cutting out, replacing and drying. A survey from above and below, with photographs, catches most of it, which is why we look inside the garage as well as at the roof.
If decking is replaced, the new boards have to be laid to the right fall before the membrane goes on. Our answer on the fall a flat garage roof needs explains why that stage cannot be hurried.
When we find a problem, we show you the photograph and give you the verdict, which is one of three: repair, short-term patch, or new roof. Any change to the plan is agreed with you in writing before it goes ahead.
Asbestos adds steps, not just days
An old garage with grey fibre cement sheets is a different kind of job. HSE's guidance puts careful removal, with the sheets kept whole, in the non-licensed category. If the sheets shatter and dust fills the air, the work becomes notifiable, and a notice goes to the regulator first. HSE sets no minimum notice period.
The sheets are then lowered whole, wrapped twice and labelled, and taken away in a lockable skip with a consignment note, which our page on asbestos sheet disposal explains. That is slower than stripping felt, and for good reason.
If you suspect asbestos, read how to tell if a garage roof is asbestos first. The sooner we know what is up there, the better the programme can be planned around it.
Scaffolding, licences and building control
Most garage roofs can be reached without much scaffold, but if a structure obstructs the highway, a scaffold licence is needed under the Highways Act. In our part of West Sussex, West Sussex County Council asks for 10 working days' notice and charges £266 a month. That lead time can sit ahead of the start date, and the survey tells us whether it applies to your garage.
Building control is another possible step. Approved Document L puts a fresh flat-roof membrane in the renovation category. If that applies to your building, tell your building control body before work starts, or ask us to explain at survey. Our garage roof building regulations page sets out when.
Nothing here argues for putting the survey off. It is a reason to have one early, because the paperwork can run alongside the planning and the start date then stays firm. Small garages on busy roads are where this tends to matter most.
Weather, access and the finish
Roofing depends on the weather. A waterproof covering is laid on a dry deck, so rain, a very damp morning or a high wind can stop work for a day or hold a start date. Sea weather along the Bognor Regis coast changes quickly, so we plan for it and explain any move to you before it happens.
Access matters as well. A garage down a narrow drive, with materials to carry by hand, takes longer than one beside the road. Cars and stored items need to be moved, and neighbours may deserve a word of notice.
When the work finishes, the garage is left clear and the old covering has gone. Edges and trims are finished neatly, and you get a walk-round before we leave. For the wider picture, our garage roof replacement page runs through the stages in order.
Related questions
Timescale queries
Will I need to move my car and stored items?
Yes, in most cases the garage needs emptying, or at least clearing along the walls, because debris falls inside during stripping and decking work. We tell you what to move when the date is set, and we protect anything that cannot be moved.
Can a garage roof be replaced in the winter?
It can, on dry days. Coverings go onto a dry deck, so wet or frosty mornings may delay a start. We build a little flexibility into the date and agree changes with you as the weather develops, rather than rushing a membrane onto damp boards. Ask any firm which tasks happen on which day, and what the fallback is if a day is lost to rain. A clear answer tells you more than a promised number of days.