What Is Nail Sickness?
Nail sickness is the progressive corrosion of mild steel fixing nails used to secure concrete interlocking roof tiles during the building boom of the 1950s, 60s and 70s. The process is simple: over 50–60 years, moisture in the roof environment causes the steel nails to corrode and eventually fail completely — leaving tiles resting on the batten rather than being fixed to it.
A nail-sick tile isn't held in place. It rests on the course below by gravity and is retained by the batten only when pressed down. In calm weather this often isn't visible. In moderate to strong wind, tiles begin to lift at their tails, slide forward, and eventually drop off the roof entirely.
Why Is Hardenhuish and North Chippenham So Affected?
Hardenhuish is one of Chippenham's largest residential estates, built primarily in the 1960s and early 1970s with concrete interlocking tile throughout. In 2026, that tile is 55–65 years old — the age at which original mild steel fixings are predictably at or past their serviceable life. The same applies to Stanley, parts of Rowden, and similar estates across the north Chippenham fringe.
This isn't a quality issue with the original construction — mild steel nails were the standard fixing method of the era. It's simply the predictable result of 60 years of wet winters on ferrous metal in a porous roof environment.
How to Identify Nail Sickness on Your Property
From Ground Level
- Tiles visibly out of line or slightly forward-shifted compared to adjacent courses
- Tiles that have slid to reveal the edge of the tile beneath
- Missing tiles in multiple locations (not just one area)
- Rust staining running down tiles from fixing nail positions
Physical Test (from scaffold or safe access)
- Press down on the tail of a tile — if it rocks or moves, the nail has failed
- Lift a tile tail gently — a nail-sick tile will lift with little resistance
- Check the nail itself — corroded nails are visibly orange-brown and often reduced to a thin stub
Pattern Recognition
The key diagnostic difference between nail sickness and other tile failures is the pattern. Storm damage or individual tile failures are localised — a few tiles in one area. Nail sickness manifests across the whole roof, progressively worsening each year. If you've had tiles re-fixed by three different roofers over five years and they keep moving, the issue is systemic, not incidental.
The re-fix trap: Many Chippenham homeowners have had nail-sick tiles re-fixed two or three times by different contractors. Re-fixing a nail-sick tile with a new nail through the old corroded hole, or with a lead clip over the nail position, treats the symptom not the cause. The adjacent tiles have the same failed nails. This approach costs £150–£300 per visit and repeats indefinitely. A full re-roof costs £5,500–£8,500 and resolves the issue permanently.
Nail Sickness Survey: What We Assess
When we carry out a nail sickness survey on a Chippenham property, we assess each roof slope individually:
- Tile security test across representative tiles on each slope
- Visual inspection of nail condition at accessible tile edges
- Assessment of the degree of tile movement (rocking vs. freely slidable)
- Condition of the ridge and hip mortar
- Felt condition via loft inspection where accessible
- Gutter and fascia condition
We give a slope-by-slope condition rating and a clear recommendation: repair, partial re-roof, phased re-roof, or full re-roof. We never recommend a full re-roof where a partial or phased approach genuinely meets the situation.
Free Nail Sickness Survey
We assess each slope individually and give honest, written findings. Covering Chippenham and all of north Wiltshire.
📞 Call 01249 247 076What Are the Options When Nail Sickness Is Confirmed?
Option 1: Over-Tile Clips
Stainless steel over-tile clips can be fitted to each individual tile without removing them. This is a cost-effective solution when the tiles themselves are in good condition and only the fixings have failed — typically £1,500–£2,500 on a semi-detached. The limitation is that the clips don't address failed felt, deteriorated battens, or other age-related issues beneath the tiles.
Option 2: Phased Re-Roof
Where one slope is significantly worse than others — the south-facing slope typically shows more advanced nail sickness due to UV exposure — a phased re-roof strips and re-lays that slope with new felt, battens and tiles, leaving sound slopes for a later phase. This spreads the cost over time while addressing the worst areas first.
Option 3: Full Re-Roof
Where nail sickness is confirmed system-wide across all slopes, a full re-roof is the most cost-effective response. The cost (£5,500–£8,500 on a typical Chippenham semi) is recouped within 3–5 years compared to continued repair call-outs, and the result is a fully weatherproofed roof with a 10-year guarantee and 40–60 year service life on concrete tile, or 60–100 years on clay.
Nail Sickness and Home Sale
Nail sickness is increasingly identified in pre-purchase surveys across Chippenham. A surveyor's note of "nail sickness suspected — specialist inspection recommended" on a survey report can delay a sale, reduce an agreed price, or give buyers grounds to withdraw. Addressing nail sickness before going to market removes this risk entirely. We carry out pre-sale nail sickness surveys and provide written reports across Chippenham and north Wiltshire.