Roof repair or re-roof? The honest guide
Repair when the covering as a whole is sound: slipped tiles, one flashing, a leaking verge, most of it £150 to £450. Re-roof when the failure is systemic: slates slipping in multiple areas from nail fatigue, underlay perished across elevations, or flat roofs patched beyond saving. The age of the roof and the spread of the faults tip the balance.
Last updated: August 2026.
The one question that decides it
Forget the visible fault for a moment and ask about the roof as a system: covering, fixings, underlay, battens. Individual components fail all the time and fix cheaply, that is what repairs are for. When the failure is systemic, when the same thing is failing everywhere at once, repairs become instalments on a roof that is already done. So the honest first question is never "what's broken?" but "is this the only place it's breaking?"
Almost always worth repairing
These faults are bread-and-butter repairs, £150 to £450 in most cases, and re-roofing over any of them alone is wasted money:
- A few slipped tiles or slates: quick to refit or replace with matching stock. On slate roofs this is a £150-ish job, until it starts happening in several places at once (see below).
- One leaking flashing: chimney, valley or abutment leadwork fails in isolation all the time. Repair or partial replacement, £150 to £600.
- Ridge or verge mortar: raked out and repointed, or upgraded to a dry system, for £150 to £450. The most common coastal repair on Teesside.
- A single flat-roof failure: one split, one seam, one outlet detail, on a covering that is otherwise sound.
- Guttering and roofline faults: sagging runs, leaking unions, broken downpipes, £80 to £250.
Almost always worth re-roofing
- Nail fatigue across a slate roof: when slates slip in several areas, the fixings are failing wholesale. Refitting on new battens and felt, often reusing the sound slates, is the real fix, £5,500 to £10,000 depending on the roof.
- Perished underlay across an elevation: the tiles look fine while the felt beneath crumbles, and every driven-rain storm soaks the loft. Lifting a few tiles in a survey settles it in minutes.
- Rotten battens: if battens snap underfoot or crumble at the nail, the covering has to come off regardless.
- A flat roof with patch-on-patch: multiple repaired splits and a soft deck mean the covering and probably the deck are done. Replacement stops the annual bill.
- Sagging or structural movement: a deflected ridge or spreading eaves is structure, not covering, and needs proper diagnosis before any covering decision.
The grey area: age and arithmetic
Between the clear cases sits the arithmetic. A 60-year-old tile roof needing £400 of ridge work today will likely want valleys, verges and felt attention across the next few winters, and £400 plus £350 plus £500 begins to approach the £5,500 entry point of a re-roof with new underlay, battens and a fresh guarantee. The rough rule the trade uses: if the repair costs more than a third of replacement, and the roof is past two-thirds of its expected life, re-roof. Concrete tiles last 40 to 60 years, Welsh slate a century-plus, felt flat roofs 10 to 15, EPDM 20 to 30.
The storm-damage trap
After every big Teesside blow, door-knockers appear offering to "fix" storm damage cheap, and occasionally to re-roof houses that need nothing of the sort. Storm damage is real and often urgent, but the answer is a written quote from a survey, not a cash price on the doorstep. Genuine storm damage to a sound roof is almost always a repair.
Getting a straight answer
The fastest route to an honest call is a survey from someone happy to quote either way. Describe the fault and the roof's age in the quote form, mention the history of previous repairs honestly, and the quote will point the right direction. The cost guide prices both routes side by side.