What “nail sickness” actually means
Nail sickness on a slate roof is best approached as a specific fault rather than a general sign that the whole roof is failing. The key issue is old slate fixings corroding until slates begin to slip. A careful look at where nail sickness on a slate roof occurs and what triggers it can save a lot of unnecessary work.
Useful clues include slates slipping individually at different points across the slope, sound slates falling without obvious storm damage, and a roof of an age where original metal fixings may be corroding. None of these proves the cause of nail sickness on a slate roof on its own, but together they give a roofer a much better starting point and can help avoid replacing sound materials in the wrong place.
The slate may be sound while the fixing fails
The main possibilities are corrosion of old iron or steel slate nails, moisture and age weakening fixings, and previous patch repairs leaving surrounding old nails untouched.
Other causes worth considering are local timber deterioration around fixing points. With nail sickness on a slate roof, the important thing is to match the cause to old slate fixings corroding until slates begin to slip, rather than treating it as a general roofing fault. For nail sickness on a slate roof, that distinction can prevent work being carried out on a nearby detail that happens to look worn but is not responsible for what you are seeing.
The pattern across the roof is important
From a safe position, you can look for a scattered pattern of slipped slates rather than one storm-damaged patch. You can also note how often new slates are dropping.
It is also useful to avoid assuming every slipped slate means the slate itself has failed. For nail sickness on a slate roof, write down what you can see and, where relevant, what the weather was doing at the time. A short sequence of photographs of nail sickness on a slate roof from the same safe viewpoint can show whether the condition is changing. When checking nail sickness on a slate roof, avoid walking on the roof or leaning out of windows; the aim is to collect useful information without creating another problem.
Falling slates make this more than a cosmetic issue
This becomes more urgent if slates are falling frequently, the roof is over a public or frequently used area, and many fixings appear to be failing across the slope. With nail sickness on a slate roof, those signs suggest that waiting for a convenient time could allow more water entry, falling material or further damage.
If those warning signs are absent, nail sickness on a slate roof may not need an emergency call-out, but it is still worth arranging a proper look before the condition gets worse. In this case, change over time matters: old slate fixings corroding until slates begin to slip that has been stable for a long period is a different situation from something that has appeared recently or is becoming more obvious after each spell of bad weather.
How a roofer confirms widespread fixing failure
A roofer looking at nail sickness on a slate roof should lift representative slates to assess the remaining fixings, then judge whether the problem is genuinely isolated or widespread.
They may also need to check battens or boarding as well as the nails. Because this page is about nail sickness on a slate roof, the inspection should stay focused on that problem and the nearby details that could realistically produce it. For nail sickness on a slate roof, ask what they think has failed, what evidence supports that view, and whether the proposed work is local or part of a wider defect. A clear explanation of nail sickness on a slate roof is more useful than a quotation that simply lists materials.
When repeated patching stops making sense
Depending on what is found, a suitable repair might refix isolated slates where the surrounding roof remains sound, use suitable hooks or replacement fixings for local repairs, or consider wider stripping and reslating when fixing failure is extensive.
For nail sickness on a slate roof, the best option is the one that deals with old slate fixings corroding until slates begin to slip and leaves the surrounding roof working as it should. If wider work is proposed for nail sickness on a slate roof, ask why a local repair would not be reliable, what condition the adjoining materials are in, and whether access costs make it sensible to combine closely related repairs. The answer should make sense for nail sickness on a slate roof, not read like a standard reroofing recommendation.
This guide is general information about nail sickness on a slate roof. The cause of nail sickness on a slate roof at an individual property can only be confirmed by inspecting the relevant roof area.