Repair or re-slate: when patching stops making sense

A repair deals with a local fault. A slipped slate, a cracked tail, a failed lead flashing or a few nails that have given way are all jobs that can be fixed one at a time, without disturbing the rest of the roof. If the surrounding slates and the timbers beneath are sound, a repair can add many years.

What a repair cannot do is change the condition of the roof around it. Replace one slate in a worn field of slates and the new one sits among tired neighbours that are about to slip. That is the logic behind our rule of thumb: ask what caused the fault, and whether the cause is still present everywhere else.

Typical UK figures from MyBuilder's 2026 slate guide are £60 to £120 for one slate and £150 to £350 for five to ten. At those prices, a modest repair is often the right answer.

On a survey we weigh these signs:

• The same fault keeps returning. If slates slip again after being replaced, the fixings are the problem, not the slates.
• Failure is spread across a slope. Slates slipping or flaking over a wide area point to something affecting the whole covering.
• Nail fatigue. Nails in old roofs corrode and lose their grip. Nail fatigue means the fixings are failing across the roof, so each slate becomes a repair in waiting.
• Brittle slates. If slates crack or crumble when lifted for a repair, patching causes more damage than it cures.
• Soft or rotten battens. These timber strips are only visible once slates are lifted, and a bad run means stripping that area regardless.
• Leaks with no single source. Several damp patches in different places suggest worn underlay as well as slates.

No single item on that list settles it. Taken together, they build a picture, and we show it to you in photographs from your own roof.

MyBuilder's slate roof guide, updated in 2026, puts a slate re-roof at £100 to £180 per m² installed, with Welsh slate at £140 to £180 and Spanish at £100 to £130. Its figure for a semi in Spanish slate is £7,000 to £10,000. Checkatrade's repair guide lists natural slate repairs at £150 to £220 per m² before VAT, with access on top.

Look at what those numbers say together. Repairs charged per m² cost about as much as a re-roof per m² in Spanish slate. So once repairs cover a large part of a slope, the repair route is no longer cheap, and you also still own an old roof with the same underlying faults. Access is paid every time a roofer visits: For scaffold, MyBuilder gives about £1,125 on a full re-roof and Checkatrade £700 to £1,300.

A fair comparison asks what you will spend on repairs over the next ten years, set against a new roof that should not need much attention. We help you do that sum on your own roof.

Re-slating does not always mean all new slate. Sound slates can be sorted, reused where they match, and topped up with new or reclaimed ones of the same type. An older house keeps its own material with us, so a slate roof stays slate. Our re-slating guide explains the process once the decision has been made; this page deals with the decision itself.

Weak points can be put right at the same time. Valleys are a common one: the gutter formed where two slopes meet is where water concentrates, and a worn lead lining there can undermine slates on both sides. Read about slate valleys for what to look for.

Quality of the slate decides how much can be saved. Our note on Spanish slate quality covers why the grade of replacement slate deserves a question.

Re-roofing a small part of a roof is normally outside the Building Regulations approval process. The Planning Portal sets the limits: below 25 per cent of the building envelope and below 50 per cent of the roof, an application is not normally required. Past them, approval applies and Part L may bring an insulation upgrade.

So the repair or re-slate choice can change the paperwork. If the work is notifiable, the consent paperwork is ours to handle. Raise a listed house, or one inside a conservation area, with Stroud District Council's planning team early. Your quote shows VAT, which roofing work normally attracts at 20%.

We start with the survey. From outside and in the loft we photograph each slope and the loft side of the slates and battens, and note which faults repeat. You see the same photographs. Then we put two options on paper: a repair list with each job priced, and a re-slate whose parts, from access to making good, each carry a price.

Sometimes the sensible answer is a repair now and a re-slate in a few years, and we will put that to you plainly. Sometimes the faults are so widespread that repairing is false economy. The decision is yours, and it is made on the quote in front of you. Either way, we tidy the site and carry the waste off, and a written 10-year workmanship guarantee goes with the job.

To get started, send photographs of any slipped slates and the loft, or ask for a survey. More about the service is on our slate roofing page.