Guide
Slipped roof tiles and slates: causes and what to do
Short answer
A slate or tile slips when its fixing fails. On stone slate roofs, the wooden peg rots or the lath breaks. On Welsh slate, the nails rust. On tiled roofs, the nib or the nail breaks. One slipped piece lets water in, so get a roofer to re-fix it soon. Do not climb up yourself.
Why roof tiles and slates slip
Tiles and slates slip because the thing that holds them has failed. The cause depends on the roof material.
Cotswold stone slates hang from a wooden peg over a lath. Oak pegs and old laths rot over many decades. When a peg breaks, the slate slides down. Cotswold District Council guidance explains this traditional fixing.
Welsh slate is nailed to battens. Over time the nails rust through. Roofers call this nail sickness. Because the nails on one roof are the same age, many slates can slip over a few years.
Clay and concrete tiles hang on battens by a nib, and some are also nailed. A nib can break, or a batten can rot. Storm winds can also lift any loose piece.
What you can check safely
You can learn a lot from the ground and the loft. Do not go onto the roof, and do not lean a ladder against a stone slate roof.
- Use binoculars to look for gaps, slates that sit lower than the rest, and pale lines where a slate has moved.
- Look in the gutter and on the ground for pieces of slate, pegs or mortar.
- Go into the loft on a bright day. Look for daylight, wet timbers, damp insulation and stains.
- After heavy rain, check the ceilings in the top rooms, especially under valleys and near chimneys.
- Take dated photos. They help the roofer and your insurer.
What to do while you wait for a roofer
Your aim is to stop water damage and keep people safe. A roofer does the repair.
Put a bucket or tray under any drip in the loft. Move stored items away from the wet area. If a slate hangs over a path or a door, keep people away from it until the roofer comes.
Do not use roof sealant, foam or tape from inside or outside. These can trap damp in the timbers and make a proper repair harder.
When to call a roofer
Call a roofer as soon as you see a slipped or missing piece. A small gap lets in more water each time it rains, and wet laths fail faster.
Ask for a roofer who knows your roof material. Stone slate needs a specialist. Our page on Cotswold stone and slate roofs lists local firms that say they do this work.
Several slipped slates on one slope often mean the pegs, nails or laths are failing across that slope. The roofer may suggest re-laying the slope. Ask them to show you the evidence, such as photos of rotten laths or rusted nails.
If the house is listed, tell the roofer at the start. Small, like-for-like repairs often need no consent. A re-lay or a change of material may need it.
How a roofer fixes a slipped slate
For a single slate, the roofer lifts the slates above it and hangs the slipped one back in place. On stone slate, they use a new peg or a discreet fixing. On Welsh slate, they often use a small metal clip, or a strip of lead called a tingle.
Ask the roofer which fixing they will use, and whether it suits your roof. On a listed roof, the method should match the original where it can.
What it may cost
The cost depends on access, the roof material and how many slates have slipped. A single slate on a low roof costs far less than a slope that needs re-laying.
Our guide Roof repair costs in the Cotswolds explains what changes the price of a repair. If the roofer suggests a larger job, read our Re-roofing cost guide as well.
Questions
Is one slipped slate an emergency?
Not usually, but do not leave it. Get it fixed within days or weeks, before the next spell of heavy rain. If water is coming in, treat it as urgent.
Does home insurance cover slipped slates?
Storm damage is often covered. Wear and tear, such as rotten pegs or rusted nails, is often not. Check your policy and ask your insurer.
Can I re-fix a slate myself?
We do not suggest it. Work at height is dangerous, and stone slates are heavy and break easily. A roofer has the right access equipment.