Nail sickness is the progressive corrosion of galvanised roofing nails that fixed concrete tiles on 1960s–70s houses. As nails fail, tiles slip. It affects most estate housing in Salisbury, Amesbury and Andover now. Repair costs £400–£900; full re-roof £5,500–£9,000. Free assessment: 0172 223 9611.
If you live in a house built between approximately 1960 and 1980 in Salisbury, Amesbury, Bishopdown, Bemerton Heath, Durrington or any of the surrounding Wiltshire estate towns, nail sickness is the most likely roofing issue you will face. It accounts for more repair and replacement calls in this area than any other single cause. This guide explains exactly what it is, how to diagnose it, and what your options are.
What Is Nail Sickness?
Nail sickness is the progressive failure of the galvanised wire nails used to fix concrete interlocking roof tiles to their timber battens during the building boom of the 1960s and 1970s. Every concrete tile on a typical Wiltshire estate house from this era was fixed using a single galvanised nail through a pre-formed hole in the tile head.
Galvanising extends the life of a steel nail in outdoor conditions, but it does not last indefinitely. The design life of the galvanised coating on 1960s-70s roofing nails was approximately 40–60 years in British conditions. Most of the housing stock built during this period across Salisbury's estates is now 50–65 years old — precisely in the window when nail corrosion becomes widespread and tiles begin to move.
BS 5534, the British Standard for slating and tiling, now requires mechanical fixing of every tile — a direct response to the nail sickness failures seen across galvanised-nailed roofs from the 1960s–70s.
— BS 5534:2014
What Causes the Nails to Fail?
The failure sequence is consistent across affected properties:
- The galvanised zinc coating erodes through years of moisture cycling — particularly relevant in Wiltshire's wet autumns and winters
- The exposed steel shank corrodes, losing cross-sectional area
- The corroded nail can no longer hold the tile against wind loading
- Tiles begin to slip — first one or two, then progressively more as the remaining good nails bear additional load from their neighbours
- Slipped tiles expose the felt underlay, which was not designed to be the primary weather barrier
- Felt failure follows, and water ingress begins
How to Spot Nail Sickness on Your Roof
From ground level, look for:
- Tiles sitting lower than their neighbours on the same course — the classic presentation where a tile has slipped down 1–3cm from its correct position
- Tiles that have slipped sideways, exposing the edge of the tile below
- Broken tiles at the corners or edges from where they have moved under wind loading and knocked adjacent tiles
- Irregular courses — a straight line of tiles that has developed a wave or dip
From the loft, with a torch:
- Daylight visible between tiles — gaps where slipped tiles have moved
- Water staining on the felt — dark patches or tide marks on the underlay surface
- Tiles that move when pushed from below — a nail-sick tile will rock when pushed up
- Corroded nail heads visible on the battens — orange-brown rust staining around the nail positions
Important: Not all slipped tiles are nail sickness. Storm damage displaces tiles without nail corrosion. If you have a single slipped tile after a high wind event, that is probably storm displacement, not nail sickness. Nail sickness presents as multiple tiles failing progressively across a slope over months and years.
Repair or Replace? The Decision Framework
The right answer depends entirely on how far the nail sickness has progressed:
| Extent of nail sickness | Recommendation | Typical cost (3-bed semi) |
|---|---|---|
| Under 15% of tiles affected | Targeted repair — renail affected sections | £400–£900 |
| 15–30% affected | Repair now, budget for re-roof in 5–8 years | £700–£1,500 |
| 30–50% affected | Compare repair and re-roof costs; re-roof often better value | £1,500–£3,000 repair vs £5,500–£8,000 re-roof |
| Over 50% affected | Re-roof — repeated repair is not cost-effective | £5,500–£9,000 |
Why Is Nail Sickness So Common in Salisbury?
The Salisbury area, including Bishopdown, Bemerton Heath, Durrington, Larkhill and the New Town estates of Andover, all expanded significantly during the 1960s and 1970s. The same era of housing stock, the same fixing specification, and the same 50–60 year deterioration timeline — which lands squarely in the present decade. We diagnose nail sickness on multiple properties every week across this area. If your property is from this era and you have had a tile slip in the last year, a professional inspection is strongly recommended.
We offer free roof surveys across Salisbury and all surrounding areas. We will assess the extent of any nail sickness, give you both repair and replacement options costed, and leave you to make the decision without pressure.
📞 Call 0172 223 9611Last reviewed: 21 July 2026 by Salisbury Roofing Experts