Rayner’s Roofing service
Garage Roof Replacement and Repair
Reliable garage roof replacement for local homes
Many garage roofs were built with a thin covering over a simple board deck, and they are easy to forget about until water starts dripping onto whatever is stored inside.
We look at the covering, the boards underneath, the edges and the gutter before recommending a repair or a full replacement.
Replace or overlay?
Overlaying means laying a new covering on top of the old one. It only works when the existing roof is dry, firm and reasonably level, and when the extra layer will not trap moisture. On many garages the old felt has been letting water in for years, so the boards are swollen or soft. Stripping back lets the deck be seen and fixed, and gives the new covering a clean, sound surface to bond to. We explain which approach suits your garage after looking at it.
Checking the deck
The deck is the layer of boards the covering sits on. Signs that it has failed include sagging between the joists, soft spots, boards swelling at the edges and staining or daylight visible from inside the garage. The joists themselves can also rot where water has sat for a long time. Any damaged boards or timbers are replaced before the new covering goes on, because even a good membrane will not last on a rotten base.
Falls, edges and the gutter
A garage roof needs a slight fall towards the gutter so that rain runs off. Older roofs were sometimes laid almost dead level, which lets water pond and work its way into the weakest joint. Along the low edge, a drip trim must discharge cleanly into the gutter; on the other edges, trims stop the wind lifting the covering. If the garage adjoins the house or a neighbour’s garage, that junction needs an upstand or flashing. We check the gutter and downpipe at the same time, because a blocked outlet will flood even a brand-new roof.
Choosing a covering
Single-ply membranes, liquid fibreglass systems and built-up felt are all used on garage roofs. Each has its own strengths when it comes to joints, installation and how well it copes with being walked on. Our flat roof comparison guide sets out the differences, and we talk through the options for your garage before quoting.
Garage roof repairs
Not every garage needs a new roof. A single split, a lifted edge trim, a failed flashing against a wall or a blocked outlet can often be repaired on its own. If leaks are showing up in several places, or the deck is soft underfoot, replacement usually gives a better result than patching.
Older sheet roofs
Some older garages have corrugated or flat sheet roofs rather than felt. If there is any chance the sheets contain asbestos, they must be tested and dealt with by a licensed specialist before any roofing work takes place. Tell us what your roof looks like when you get in touch so we can advise on the right first step.
Before work starts
It helps to move anything valuable or fragile away from the area under the roof and to make sure the driveway or path is clear for access. If the garage is joined to a neighbour’s, agree the work with them first. Our written quotation sets out what is included, such as stripping, boards, trims and gutter work.
Related guides and services
Frequently asked questions
How do I know if my garage roof needs replacing?
Repeated leaks, a sagging or spongy surface, widespread cracking or blistering and damp boards visible from inside all suggest replacement. A single leak with a firm deck can often be repaired instead.
Can I replace my half of a shared garage roof?
It is possible, but the joint with the neighbouring roof must be sealed carefully. Replacing both together often gives a better result, so it is worth speaking to your neighbour first.
Do I need to empty the garage?
You do not always need to empty it, but moving valuables and fragile items away from the roof is sensible because dust and debris can fall when the old covering is stripped.
Does a garage roof replacement need planning permission?
Replacing a garage roof like for like does not normally need planning permission. If you plan to change its height or shape, or the property is in a conservation area, check with your local council first.
Is the gutter included?
We check the gutter and downpipe as part of the job and include any repair or replacement in the written quotation if it is needed.