Why do roof tiles crack and slip?
Most broken tiles have been stood on. Antenna installers, solar crews, air conditioning techs and helpful relatives all cross tiled roofs, and a tile only takes a person's weight well where it overlaps the one below.
Others crack from age, a falling branch or hail. A slipped tile usually means a broken nib (the small lug on the back that hooks over the batten) or a tile that was never seated properly. Concrete tiles lose their colour coating as they age, which Monier says is cosmetic and doesn't affect waterproofing. Terracotta keeps its colour but can chip along the edges.
How does a roofer replace a tile?
Most tiles are held by their own weight and the interlock with their neighbours, with some clipped or nailed along the edges. The roofer eases up the tiles above the broken one, slides it out, fits the replacement and settles everything back down. Tile maker Monier makes the same point: damaged tiles get replaced one at a time, not the whole roof.
If the cracked tile sits right under the ridge or a hip, the capping above it may need lifting and rebedding, which turns a small job into a bigger one. That's covered on our ridge capping page.
What if your tiles aren't made any more?
Profile matters more than colour. A tile with a slightly different shape won't lock in properly and can let water through, even if it looks close from the street.
Colour is easier with terracotta, because Monier says its fired-in colour doesn't fade. Concrete tile coatings do fade and weather, so a new concrete tile can look brighter than its neighbours for a while.
When a profile is out of production, roofers look for second-hand tiles from recyclers and demolition yards. Another common trick is to take sound tiles from a slope at the back you can't see, use them at the front, and put the odd ones out of sight. Our page on reclaimed roof tiles explains the trade-offs.
Tiles: what's yours and what isn't
You can
- Scan the roof with binoculars from across the street or an upstairs window for cracked or crooked tiles
- If solar or antenna installers were up there lately, ask them to come back and check what they walked on
- Keep any spare tiles the builder left behind, and tell the roofer you have them
- After rain, look for drips on the ceiling below the spot you're worried about
Leave to a roofer
- Lifting, replacing or re-seating tiles
- Tiles next to ridges, hips and valleys
- Deciding whether worn or chipped tiles are still worth keeping
- Checking every slope for more cracks while they're up there
If it were our roof
With a handful of broken tiles and the rest solid, we'd have those replaced and ask the roofer to walk every slope while they're up there, because cracked tiles rarely come alone. If they report tiles cracking or crumbling across the whole roof, that's a different conversation. Our guide to cracked tiles helps you weigh a repair against something bigger.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.
