Nail sickness is the corrosion failure of the nails holding roof tiles or slates, causing tiles to slip even though the tiles themselves are sound. It affects most East Yorkshire properties built between 1955 and 1985. Repair suits isolated cases; widespread failure needs a recover, typically costing £5,000 to £9,000 on a standard semi.
If you own a property built in East Yorkshire between roughly 1955 and 1985, nail sickness is probably the most important roofing term you've never heard. It's responsible for a significant proportion of the re-roof enquiries we receive across Beverley, Hull and the wider East Riding — and it frequently gets missed by homeowners until a storm event makes the consequences undeniable.
What Is Nail Sickness?
Nail sickness is the progressive failure of the iron or steel nails that fix concrete or clay roof tiles to the timber battens beneath them. When these nails were installed in the 1960s and 70s, they were galvanised against corrosion. That galvanisation has a finite lifespan. In the persistently damp East Yorkshire climate, with its Hull Valley humidity and pronounced freeze-thaw cycling, iron fixings typically fail within 50–70 years.
As the nails corrode, they lose their grip. The tiles they were holding are now resting on the battens — not fixed to them. In calm conditions, the weight of adjacent tiles keeps everything in place. In a moderate gale — common enough in East Yorkshire from September through March — those loose tiles displace. What was a £200 preventive nail-fixing job becomes a £400 storm call-out, with potential internal water damage on top.
Key fact: Nail sickness progresses slowly and invisibly across the whole roof before it becomes apparent. A property can appear completely sound for years before a single storm event reveals the full extent of the problem.
Which Properties Are Affected?
BS 5534 requires that all roof tile and slate fixings be specified by calculation for the site's wind exposure, and recommends austenitic stainless steel fixings in locations where corrosion risk is elevated.
Source: BS 5534:2014+A2:2018, Code of practice for slating and tiling
The nail sickness problem is concentrated in properties built with concrete interlocking tile between approximately 1955 and 1985. In Beverley, this means the Grovehill Road and Swinemoor Lane areas — substantial post-war developments now 50–70 years old. In Hull, it's Bransholme (HU7), Orchard Park (HU6), and the east Hull estates in HU8 and HU9. The Cottingham and Willerby suburban belts are also heavily affected.
How to Spot It From Ground Level
You don't need to go on the roof for an initial assessment. From street level or the garden, look for:
- Tiles standing slightly proud — one end lifted 5–10mm above adjacent tiles in an otherwise flat course
- Irregular alignment across a slope that should be uniformly flat
- Tiles that have slipped slightly out of position, showing a gap at the head of the tile below
- Any tile rocking visibly in a stiff breeze
From the loft, the picture is clearer: tiles that move when pressed gently from below, visible gaps around old nail holes, and felt that's been exposed to moisture for years through micro-gaps above.
Repair vs Replace: Making the Right Call
If nail sickness is limited to one pitch or a specific section — fewer than 20% of tiles across both pitches — targeted section replacement is cost-effective and buys another 20–30 years. If it's widespread, a full re-roof is almost always better value. Repeated section repairs on an ageing substrate with compromised felt rarely pay for themselves compared to a complete replacement under a 10-year guarantee.
The Chemistry of Nail Corrosion
Nail sickness is an electrochemical process. Iron and steel corrode in the presence of moisture and oxygen, and the rate accelerates markedly with the presence of chlorides — which is why coastal and estuary properties suffer earlier failure. Original Victorian nails were plain wrought or cut iron with no protective coating, and their service life in East Yorkshire's damp climate runs to roughly 80–120 years.
Mid-twentieth-century nails were generally galvanised, relying on a sacrificial zinc coating. Zinc protects the steel beneath until it is consumed, at which point corrosion proceeds rapidly — which is why galvanised fixings fail somewhat abruptly rather than gradually, and why a roof can appear sound one year and shed several tiles the next. Modern practice uses austenitic stainless steel, which does not depend on a coating and effectively removes the failure mode.
Why the 1960s and 1970s Are the Peak
The concentration of nail sickness across Willerby, Bransholme, Orchard Park, Molescroft and Grovehill is not a coincidence of construction quality — it is a demographic effect in the housing stock. East Yorkshire, like most of the country, built at unprecedented volume between the mid-1950s and the late 1970s, and those roofs were fixed with galvanised nails whose coating is now consumed.
The result is that a large proportion of the region's housing reaches the same failure point within a comparatively narrow window. It also means that on any individual estate, when neighbouring properties start losing tiles, yours is likely to be on a similar timeline — the construction date, the fixing specification and the exposure are all effectively identical.
Confirming the Diagnosis
Nail sickness is diagnosed by lifting tiles and examining the fixings, not by counting slipped tiles from the ground. A roofer lifting a tile on an affected roof will find nails that are heavily corroded, reduced in section, or that snap under light pressure — and crucially will find this at multiple points across the slope rather than at one location.
The distinction matters because the alternative diagnoses have very different remedies. A tile that has slipped because its nib broke is a discrete failure and a simple replacement. A tile that has slipped because it was never nailed in the first place — common in the field of older roofs — is also localised. Only widespread fixing failure justifies a recover, and any contractor recommending one should be able to describe what they found when they lifted tiles, at how many points, and on which slopes.
Partial Recovering by Slope
Nail sickness rarely progresses evenly. South and west-facing slopes, which undergo greater thermal cycling and wetting-drying, commonly fail before north and east slopes on the same house. It is entirely legitimate to recover the failing slope and leave the sound one, and on a large or complex roof it can halve the immediate cost.
The considerations are appearance and sequencing. A newly recovered slope alongside a weathered original will look different, which matters more on a prominent elevation than a rear one. And the second slope will need doing eventually, meaning a second access cost — so where both slopes are close to the threshold, doing them together is usually better value. A survey that reports slope by slope gives you the information to make that judgement.
What a Recover Actually Involves
A recover on a nail-sick roof is not simply refixing the existing tiles. The correct sequence is: strip the covering, remove old battens and felt entirely, inspect rafters and wall plate and carry out any timber repairs, lay new breathable membrane, fix new treated battens at the correct gauge, and re-lay the covering — salvaged tiles where they are sound, supplemented with matched material.
All lead is renewed rather than reused, ridge and hip are converted to dry fix where conservation constraints allow, and the verge is properly detailed. The result is a roof with an entirely new fixing system and underlay, typically good for another 40–60 years, using a substantial proportion of the original covering. On a Victorian slate roof in Beverley the salvage rate is often 60–80%, which is why a recover on a period property is frequently far less expensive than owners expect.
Free survey, no call-out fee. Call 0148 290 8437 or book online.
What Does It Cost?
| Scope | Typical Cost | Notes |
|---|---|---|
| Section re-tile (one pitch) | £1,500–£3,500 | Depends on area and tile type |
| Full re-roof, 3-bed semi | £5,000–£9,000 | Concrete or clay interlocking |
| Full re-roof, Victorian terrace | £6,000–£11,000 | Slate or clay plain tile |
| Survey only | £80–£150 | Written report, no obligation |
Last reviewed: 22 July 2026 by Beverley Roofing Experts.
Frequently Asked Questions
Nail sickness is the progressive failure of the iron or steel nails that fix concrete or clay roof tiles to the batten beneath. As nails corrode over 50–70 years, they lose their grip. Tiles rest loose on the battens and displace in wind. It's endemic on East Yorkshire post-war housing stock built between 1955 and 1985.
Look for tiles standing slightly proud of adjacent tiles on an otherwise even slope — one end lifted 5–10mm. Irregular tile alignment across a pitch that should be flat. Any tile that appears to rock in wind. From the loft, press tiles gently upward — nail-sick tiles move freely whereas sound tiles resist firmly.
The worst-affected areas are the 1960s–80s concrete tile estates: Grovehill and Swinemoor in Beverley, Bransholme and Orchard Park in Hull, and the Cottingham and Willerby suburban belts. Properties built between 1955 and 1985 are at or past the threshold for iron nail failure in East Yorkshire's damp climate.
If nail sickness is limited to one pitch or one section — fewer than 20% of tiles — targeted section replacement is viable and cost-effective. If it's widespread across both pitches, a full re-roof is almost always better value. Successive section repairs on an ageing felt substrate with widespread nail failure rarely pays off long-term.
Generally no. Insurance covers sudden unexpected events. Nail sickness is gradual deterioration — a maintenance issue. Some policies have limited cover for resulting sudden damage (a tile displaced in a storm) but the underlying nail sickness repair itself is not an insured event.
Section re-tile on one pitch typically costs £1,500–£3,500 depending on area and tile type. Full re-roof on a 3-bed semi runs £5,000–£9,000. We always survey before quoting — call 0148 290 8437 for a free assessment.
Iron nail fixings typically last 50–70 years in East Yorkshire's damp climate before significant corrosion compromises their grip. The process is slow and invisible until a wind event reveals the extent. Properties built in the 1960s–70s are now at exactly this threshold — many will have advanced nail sickness that isn't visible from the ground.