What is nail fatigue on a slate roof?
The short answer
Nail fatigue — often called nail sickness — is the gradual corrosion and weakening of the nails holding slates in place. Because they were all fitted at the same time and share the same exposure, they tend to fail in the same period. The slates themselves may be in excellent condition.
What evidence should you look for?
Slates slipping progressively across a slope, mostly undamaged.
- What it can mean
- The fixings are failing while the covering remains sound.
- What else could explain it
- Batten decay releases slates in the same way and looks identical from the ground.
Investigate · Inspection needed to confirm
What could this mean?
Where the slate is sound, stripping and re-laying with new fixings, underlay and battens is often the proportionate answer — and reuses most of your existing material.
What this evidence cannot tell you
Nail fatigue cannot be confirmed from the ground or from imagery. It is established by examining nails recovered from slates that have slipped or been lifted.
What are the realistic options?
Broader repair
Fixing failure confined to one area of one slope.
Partial renewal
A slope on which fixings are failing generally but the slate is sound.
A wider scope should be justified by what the evidence shows, not assumed.
Related services
- Slate RoofingSlate roofing uses natural or reclaimed slate laid in courses with a head lap set by the roof pitch and site exposure. It is the traditional covering across Cumbria and, correctly fixed, is among the longest-lasting roof coverings available.
- New Roofs and ReroofingReroofing means stripping the existing covering back to the rafters and rebuilding the roof with new membrane, battens, fixings and coverings. It is the right choice once slates or tiles are failing across whole slopes or the underlay has perished.
What should you do next?
Ask whether the slate can be reused if the roof is re-laid — it frequently can, and it changes the cost significantly.
Reviewed by Aaron, Owner, Elite Roofing Services Cumbria Ltd — last reviewed .
Related questions
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