Commercial roof repair
Reactive repairs · flat, metal and panel roofs · UK-wide
Most commercial roof leaks come from a handful of places: blocked outlets and gutters, split laps and seams, failed flashings at upstands and plant, and corroded sheet ends. A repair contractor finds the source, which is rarely directly above the drip, makes it watertight and tells you whether the rest of the roof is going the same way.
Reactive repairs are usually priced per visit, from a roofer's day rate of about £250 to £350 per operative plus access. Published rates, checked November 2026.
Signs a repair will do
One leak, a known cause
Water under a blocked outlet, a split at one lap, a lifted flashing after a storm. Fix the cause and the roof goes on working.
The roof is under about 15 years old
A younger roof with a local defect is worth repairing. Check whether it is still under a guarantee before anyone else touches it.
The deck and insulation are dry
A core sample next to the leak shows whether water has spread. Dry insulation means the repair stays local.
You need time to budget
A sound repair buys a year or two to plan a refurbishment properly, rather than replacing a roof in a hurry.
Typical repair costs
| Item | Scope | Typical cost |
|---|---|---|
| Roofer day rate | Per operative, outside London; London and the South East 20 to 30% more | £250 to £350 |
| Small access scaffold | For a short repair on a low building | £600 to £1,000 |
| Condition survey after the repair | Full survey of a smaller roof, written report | £250 to £400 |
| Drone inspection | Photographs of areas nobody should walk on | £200 to £350 |
| Patch, flashing or lap repair | Depends on access and system | Per visit |
Budget figures read from national price guides and roofers' own published rates in November 2026, shown before VAT. Use them to plan; the contractor's written price is what counts. Work out a budget for your roof.
Where leaks come from
Outlets, gutters and ponding
Flat roofs fail first where water sits. A blocked outlet turns a section of roof into a pond, and standing water finds any weak lap. Valley and box gutters on metal roofs overflow into the building when leaves and silt build up. Clearing outlets twice a year prevents a large share of the call-outs facilities teams make.
Laps, seams and flashings
On felt roofs, laps lift and blisters crack as the bitumen ages. On single ply, seams can open if the original welding was poor. Flashings at upstands, parapets, rooflight kerbs and around rooftop plant move with the building and crack. These are classic local repairs.
Metal sheets and fixings
On profiled metal roofs, rust at the cut ends and side laps, perished fixing washers and failed rooflights are the usual causes. One rusted sheet can be replaced; rust along every lap is a sign the roof needs cut edge treatment or overcladding.
When a repair stops making sense
If the same roof needs repairs every few months, cores show wet insulation across large areas, or the roof is past the end of its expected life, money spent on patches is wasted. That is the point to look at refurbishment or replacement.
Where our information comes from
Prices are typical ranges from published UK contractor price guides and roofing firms' price pages, November 2026.
A leak this week? Describe the building and the roof to get a repair priced by a contractor who covers your area.
Get contractor quotesHow the job runs
Reactive repairs move faster than planned work, but the order stays the same.
Make safe
Buckets and sheeting inside, power isolated near the leak if needed. Do not send staff onto the roof: treat every roof as fragile until a competent person says otherwise.
Find the source
The contractor traces the water, often some metres from where it appears inside, and checks outlets and gutters first.
Repair and record
A lasting repair in a compatible material, with before-and-after photographs.
Report
A short note on the roof's overall condition and what to plan for next.
Repair questions
How much does a commercial roof repair cost?
- Most reactive repairs are priced per visit from a roofer's day rate, typically £250 to £350 per operative outside London, plus access. A small access scaffold is around £600 to £1,000. Large or high roofs needing mobile platforms or edge protection cost more. Ask for the access cost to be shown separately.
Who pays for roof repairs on a commercial lease?
- It depends on the lease. Under a full repairing and insuring lease the tenant is usually responsible for the roof; on multi-let buildings the landlord often repairs it and recovers the cost through the service charge. Read the repair clause and ask your surveyor or solicitor before instructing work.
Can a leak be repaired in the rain?
- Temporary repairs can. Most permanent repairs on felt, single ply and liquid systems need a dry surface, so a contractor may make the roof safe on the first visit and return to finish it.
Should I repair or replace?
- Repair a sound roof with a local defect. Look at refurbishment or replacement when leaks keep returning, the insulation is wet over large areas, or the roof is past its expected service life. A survey with cores settles it.
Will a repair void the roof guarantee?
- It can, if someone other than an approved installer works on a roof still under a manufacturer's guarantee. Check the guarantee paperwork first and call the original installer if it still applies.
Read next
- Roof surveys and maintenance
Find out how long the roof has left.
- Commercial roof refurbishment
When repairs stop making sense.
- Cut edge corrosion treatment
Rust at sheet ends and laps.
- Commercial roof cost calculator
Budget for bigger work.
Get a roof repair priced
Three short steps. The postcode, what the roof is and what it is doing is enough to start. A contractor confirms the detail on a survey.
Your request stays with us until you approve the independent commercial roofing contractor we put forward for your building.
Received. Here is what happens next.
- We look for an independent commercial roofing contractor who covers your area and takes on roofs like yours, then email or phone you with their name.
- Nothing goes to them until you say yes.
- If you agree, they arrange a survey and send a written price. No newsletters and no sales calls from us.