A huge proportion of the housing stock in Glasgow and Edinburgh is natural slate on timber sarking, often original and often well past a hundred years old. Slate itself can outlive us all. The fixings usually cannot.
Nail sickness: the failure that matters
Slates are held by nails. When those nails corrode, slates begin to slip one at a time with no obvious pattern, usually starting on the most weather-exposed elevation. Two or three slipped slates in a season on the same slope is the classic signature. Replacing them individually works, but if the nails are going everywhere, you are buying time rather than fixing the roof.
Signs you can spot from the ground
- Slates sitting slightly proud, out of line, or with visible tabs and clips holding them.
- Slate fragments in gutters and on paths — slate delaminates in layers as it ages.
- Dark, damp-looking patches on the sarking visible from the loft on a bright day.
- Rust staining running down from individual slates, which points straight at the fixings.
Patch, strip-and-relay, or full recover?
- Patch repair — right when the slate is sound and only a few fixings have gone. Roughly £150–£400 per visit.
- Strip and relay reusing sound slates on new battens and felt — right when fixings have failed widely but the slate is good.
- Full recover with new or reclaimed slate — right when the slate itself is delaminating across elevations.
The decision hinges on the condition of the slate versus the condition of the nails. Those are two different questions, and both are answerable from close-range photographs.
Tenements and shared roofs
In Scottish tenements the roof is usually common property and costs are shared between flats. Getting agreement is much easier with a dated, independent photographic report showing exactly which slopes are failing than with a single roofer's quote that other owners suspect is padded.
Getting a straight answer
Our drone survey captures every elevation at close range without scaffold or a ladder against the wall — useful on tenement heights. Each defect is circled, described and graded, so you can see whether you are looking at three loose slates or a slope that has run out of fixings. £99 residential, £149 commercial.