A reference guide to roof repair on British homes. What each fault actually is, the method a roofer will use, how long it should hold and the point where patching becomes false economy.
The eight faults behind most repair calls
Across a working year in Oxfordshire the same faults come round again and again: slipped or missing tiles, cracked or loose ridge and hip tiles, failed lead flashing at a chimney or abutment, blocked or split valleys, splits and blisters in flat roof coverings, perished mortar bedding, corroded or misaligned guttering, and rotten timber at the eaves.
Almost every leak traces back to one of those. The skill is not in knowing the list, it is in working out which one is responsible when the water shows up three metres from where it got in.
Tiles and slates: what a proper repair looks like
A slipped concrete or clay tile is relifted onto its batten and, where the nib has broken, secured with a clip or a copper nail. A broken tile is replaced with a genuine match rather than the nearest colour on the merchant's rack, because a mismatched patch on a front elevation is visible from the pavement for the next forty years.
Slate is different work. Individual slates are refixed with a tingle, a strip of lead or copper folded over the tail, because you cannot nail a single slate in the middle of a covered field. If a roofer proposes to mortar a slate back, that is a shortcut and it will fail.
Ridges, verges and mortar work
Mortar bedding on ridge and verge has a life of roughly 20 to 30 years before it cracks and lets go. Repointing over failed mortar rarely lasts. The correct repair is to lift the tiles, clean off the old bed, and rebed in a 3:1 sand and cement mix, or convert to a dry fix system with mechanical clips and a ventilated ridge roll.
Dry fix costs more up front and removes the recurring maintenance, which is why building regulations have pushed new work that way since 2015. On a heritage property in a conservation area, bedded mortar may still be the appropriate finish.
Lead and flashing repairs
Lead fails at the fold, at the fixing and at the joint. Cracks along a chimney apron usually mean the lead was run in a single length that was too long, so thermal movement tore it. The fix is to renew in shorter bays with proper laps, chased into the brickwork and wedged, not smeared with mastic.
Sealant applied over failing lead is the most common bodge we are called out to undo. It hides the problem for a winter and then peels, and by then the timber underneath has usually taken water for months. Our chimney and lead work guide covers the warning signs to look for from ground level.
What repairs cost and what drives the number
Small access reachable repairs such as a handful of tiles or a short section of gutter typically run £150 to £400. Rebedding a ridge line, renewing a chimney flashing set or opening up and relining a valley is more often £450 to £1,600 depending on length and access.
The single biggest variable is scaffolding. A repair that takes a roofer two hours can carry a scaffold cost that dwarfs the labour, which is why grouping several small jobs into one visit almost always saves money. Our scaffolding cost guide explains those figures.
When repair stops being the right call
Repairs make sense while the failures are local and the underlying structure is sound. Once you are replacing tiles across the whole slope, the felt beneath has torn at every batten, or the third repair in two years has just failed, money spent on patching is money taken away from the covering that would solve it.
We say so plainly on site. If a roof has ten good years left we will tell you to keep repairing, and if it does not we will show you photographs of why. Our repair versus replacement guide sets out how that judgement is made.
How soon does a roof repair need doing?
Anything letting water in should be dealt with within days, because the damage inside compounds faster than the roof damage itself. A single displaced tile with no water ingress can usually wait for settled weather.
Do you guarantee repair work?
Yes. Repairs carried out by us are guaranteed as set out in the terms we give you with your written quotation, and we come back if something we fixed fails.
Can most repairs be done without scaffolding?
Low level and eaves work often can, using a tower or ladder access safely. Ridge, chimney and valley work almost always needs a scaffold, both for safety and to do the job properly.
Will one repair fix a leak that has appeared in several rooms?
Not always. Water travelling along battens and rafters can appear in more than one place from a single entry point, but multiple entry points are just as common. That is why we trace rather than guess.
Is it worth repairing a roof before selling a house?
Usually yes for visible faults, because a surveyor's report noting slipped tiles or failed flashings tends to cost more in price negotiation than the repair itself.
Do you repair roofs you did not install?
Yes. Most of our repair work is on roofs built by others, including ones where a previous repair has not held.
Not sure which repair your roof needs?
Send us a photograph or let us take a look. You get a straight answer, a written price and no pressure to book anything.
Evans Roofing & Maintenance Ltd, Witney, Oxfordshire. Call 07960 482233 for a free written quote.