Is repointing ridge tiles enough, or do I need a dry ridge?

Repointing alone puts you back where you started, because mortar was never intended as the only fixing. BS 5534 requires a mechanical fixing for ridge and hip tiles. That can be a dry-ridge system, or ridge tiles mechanically fixed over a mortar bed — both are compliant, and a roofer should tell you which suits your roof.

How long does ridge mortar last?

There is no guaranteed figure, but bedded ridges commonly start failing somewhere between 15 and 25 years depending on exposure, mix quality and how many winters have frozen water in the joint. Coastal and hilltop roofs go sooner.

Does a dry ridge look different?

Slightly. You see a neat continuous line rather than a mortar fillet, sometimes with a visible ridge roll or a low-profile capping strip along each side. Most homeowners find it tidier; on a listed building or in a conservation area, check what is acceptable before committing.

The ridge looks fine but I have water in the loft at the top — related?

Very possibly. Mortar hollows out from the inside, so a ridge can look sound from the ground while the bed behind has gone. Water entering at the apex runs down the rafters and shows up as staining lower down, which is why the leak often appears to be somewhere else.

High risk

Updated 30 August 2026

Loose Or Cracked Ridge Tiles

The tiles along the very top of the roof are rocking, cracked, or have visible gaps in the mortar underneath.

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What's happening?

Ridge tiles cap the apex where the two roof slopes meet. Traditionally they were bedded on a sand-and-cement mortar fillet, and for decades that mortar was the only thing holding them on. Mortar is rigid, the roof beneath moves with temperature and load, and UK weather freezes water in every hairline crack — so the bed fails, hollows out, and the tiles start to rock. BS 5534 no longer accepts mortar alone as a fixing: ridge and hip tiles need a mechanical fixing, either a screw or clip through a dry-ridge system or a mechanically fixed ridge over a mortar bed. A ridge tile at the highest point of the building, unfixed, is the single most likely piece of a roof to end up on the ground.

What usually causes it?

Mortar bed carbonated and perished with age, typically noticeable from 15 to 25 years after bedding
Freeze-thaw cycling — water sits in a crack, freezes, expands, and opens the crack further each winter
Thermal movement of the ridge board and rafters that rigid mortar cannot accommodate
Mortar mixed too weak or too strong, or laid in cold or wet conditions so it never cured properly
No mechanical fixing behind the mortar, so once the bed goes there is nothing left
Wind uplift at the apex, which is the highest-suction zone on the whole roof
Cracked ridge tiles themselves, from frost damage or from being walked on during earlier work

Is it dangerous?

Yes. This is the highest point of the building, so a ridge tile that comes off falls the full height of the house and usually lands well out from the wall. They are heavy, and a cracked one breaks into edged pieces. If you can see a ridge tile visibly rocking, cordon the ground on both sides of the house. The other consequence is water: the ridge is a joint, and once mortar has hollowed out, wind-driven rain runs straight into the loft space at the apex and tracks down the rafters, which is why ridge failure often shows up as staining nowhere near the ridge.

Can I fix it myself?

Assess it from the ground and record it. Walk both sides of the house and look along the ridge line against the sky — a sound ridge is dead straight, and a dipping or stepped line means bedding has gone. Photograph the mortar joints; dark shadow lines and missing chunks are visible from ground level with a phone zoom. In the loft, look at the underside of the apex for staining, damp timber or daylight. Nothing about ridge work is DIY: it is at the highest, most exposed point of the roof, needs scaffold, and needs the fixing specification calculated. Do not repoint from a ladder.

When should you call a roofer?

Call a roofer promptly — within days if a tile is visibly loose or rocking, and treat it as urgent if one has already slid or if you have found water at the apex in the loft. A roof with a straight ridge and only cosmetic mortar erosion can wait for a planned job, but get it looked at rather than guessing, because the tile that is rocking is not always the one that looks worst from below.

What will the roofer actually do?

Erect scaffold to the ridge — this is not work that can be done safely from a ladder
Lift the existing ridge tiles, clear out the failed mortar and check the ridge board, rafter tops and underlay beneath
Recommend either mechanically fixed bedded ridge or a dry-ridge system, explain the difference for your roof and exposure, and fit it with a mechanical fixing to BS 5534 — screws or clips into a batten or ridge roll — rather than relying on mortar
Replace cracked or spalled ridge tiles with matching units, using salvage where the profile is discontinued
Check and re-fix hips at the same time, since they were bedded the same way on the same day
Confirm ridge ventilation where a dry system is used, so the loft is not sealed up in the process

Frequently asked questions

We’re happy to answer all your questions.

Sources & References

Roof Tiles Blown Off In High WindHigh risk Crumbling Mortar Along The Gable VergeCaution Water Stain On The Ceiling But No Obvious LeakCaution

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