The short answer
Treat a cracked ridge tile as a water path. A hairline crack may hold for a while, but a crack right through lets rain reach the mortar and underlay beneath, and wind can snap the tile off. The usual fix is to replace it with a matched tile and check the fixings on either side. Look up from the garden, and keep off the ladder.
Why a crack matters
Ridge tiles cap the apex of the roof, the highest line on the house. Beneath them sits a gap that must be kept dry, and below that the underlay and the roof timbers. The cap tiles are the roof's last defence along that crest.
A crack gives water a way in. Rain gets into the crack, runs through to the bedding or the fixing beneath and, over time, softens the mortar and rusts the fixings. Once the bedding or fixing under a cracked tile has weakened, the tile can work loose.
Wind is the other risk. A ridge tile is exposed, and a cracked one can split fully in a gale, with the broken piece landing in a garden or on a path. That is a safety problem as well as a leak.
The size of the crack counts. A fine hairline that does not go through may be a surface craze and can be watched. A crack you can see light through, or one that has opened with a gap, needs attention. If you are unsure, send us a photo taken with the zoom on your phone.
Replace, repair or watch
Replacement is the usual fix. A cracked ridge tile cannot be mended reliably, because filler or sealant does not stay in a tile that flexes in the wind. The old tile is lifted, the bedding or fixing checked, and a new tile set in its place.
The tiles either side matter. If the mortar is cracked and loose along the ridge, replacing one tile is a short-term patch, and the neighbours are likely to follow. Our guide to the signs of loose ridge tiles lists what to look for.
Watching is reasonable only for a hairline crack on a sound ridge. Keep an eye on it after storms and in frost, and book a visit if it widens.
Cost is modest for a single tile. Which? gives £80 to £300 ex VAT for fitting a new ridge tile, and MyJobQuote says replacing a ridge costs between £225 and £550, both as typical UK ranges. The figure goes up where scaffold is needed or where many tiles are involved.
On the survey we check the whole length of the ridge, not only the cracked tile, and photograph what we find.
Matching the tile
A replacement tile should match the old one in profile, size, material and colour. Ridge tiles come in several shapes, such as half-round, angular and segmental, and a tile of the wrong shape will not sit tightly against its neighbours.
Colour needs care. A new clay or concrete tile is brighter than one that has weathered for decades, and the patch will show for a while. On an older roof, a reclaimed tile of the same type often blends better. Our guide to types of ridge tiles explains the shapes.
If the original tile is no longer made, a close match from another range may be the best available, and we tell you so before the work. A good match is a judgement, and we show you the options in photographs against your own roof.
Where a ridge is being refixed, there is a choice of method. A new tile can be bedded in mortar with a mechanical fixing, or the ridge can be converted to a dry system tested to BS 8612. The right route depends on the length of ridge affected and its condition.
Safe checking and what to do next
You can check a ridge from the ground. Stand back from the house with binoculars or a phone that zooms well, and look along the line for gaps, tilted tiles, cracked pieces and mortar crumbling at the joints. Glance at the lawn and gutters for broken pieces too, and note where they fell, since that shows which side of the ridge they came from.
Do not climb a ladder onto the roof to look. Ridge work is at the highest point, ladders are poorly placed to reach it, and a slip from there is a long fall. A roof is no place for an amateur inspection.
If a tile has already fallen, keep the ground below clear and tell us. A leak that has started needs the roof made safe first, and a temporary cover can protect the ridge till a lasting fix is done.
Send a photo of the ridge with a note of the date and any storm, and we will read the tile and its neighbours together. The dry ridge and verge hub explains the methods, and our price follows the visit as a single written total.
