The short answer
No, mortar bedding is not banned. Since the 2014 revision of BS 5534, a mortar bed is no longer counted on by itself to keep ridge and hip tiles in place, so a bedded ridge needs mechanical fixings as well. Mortar still seals the joints and fills the gaps. The change is that clips, screws or straps do the holding, and a roofer who beds a ridge with mortar and nothing else is working to an old method.
Where the idea that mortar is banned comes from
The myth has a real origin. Until the 2014 revision of BS 5534, the standard for slating and tiling, a ridge was commonly bedded on mortar and left to its own adhesion. After the revision, the picture shifted. Marley's guidance, updated in 2026, reads the revision as settling the point: a mortar bond cannot be counted on to resist uplift by itself, and anything bedded should carry a mechanical fixing too.
Somewhere between the standard and the pub, that became "mortar is banned". It is not what the standard says. Nothing in what we have read prohibits mortar as a material. The standard says the bond is too weak to depend on, which is a different thing, and the detail is covered in our guide to BS 5534 and BS 8612.
What mortar is still used for
Mortar remains a good material for the job it does best, and plenty of sound ridges still use it. It fills the space between ridge tile and the tiles beneath, closes the open ends of the tile courses against rain and nesting birds, and gives the ridge a neat, solid finish. On a traditional roof, a bedded ridge also looks right, and on a period house the appearance carries real weight.
What mortar does badly is resist being pulled upward. Wind tries to lift a ridge from the windward side, and a bed of cement or lime in tension is a weak thing. Over the years it cracks, loosens and lets go, which is a pattern we look for first on older ridges. That is the weakness the standard recognises, and the fix is to add something that does not depend on the mortar holding.
Why old ridges fail first
Ridges laid before the revision, on mortar alone, are the likeliest to have worked loose by now. A tile that has lost its bed has no second line of defence, and one gust can take it. If you have a ridge of that age, a look from the loft or a survey is better than waiting for a tile to land in the garden.
What a compliant bedded ridge looks like
A ridge that keeps its mortar and meets the 2014 revision has the bedding plus a mechanical fixing. In practice that means stainless steel or similar fixings that tie each ridge tile through to the structure beneath, or ridge clips and straps that hold the tile independently of the bed. The mortar is still there, but it is no longer the only thing between the tile and the sky.
The fixing has to suit the tile. A half-round or angled ridge tile needs a different arrangement from a pantile ridge, and the fixing must reach something solid: a ridge board, a batten or a purpose-made bracket. We choose it at the survey from what is actually on your roof, and the quote names it, so nothing is a mystery.
Ask your roofer what is holding the ridge down besides the mortar. A clear answer, naming the fixing, is what you want to hear.
On some houses a dry-fix system is a better answer than a bedded ridge. BS 8612 covers how dry-fix verge, hip and ridge systems are tested, and Marley's advice is that only a tested product earns compliance. A dry system removes the mortar altogether, using mechanical fixings and a ventilated or sealed strip along the top. Our comparison of dry hip systems and whether they are worth it weighs that option for the hip lines.
Lime, listed roofs and a different reading
Not every roof is in the same position. If your home has a listing, or stands within a conservation area, a bedded ridge in lime mortar may be the right repair because it matches what is there, and a plastic-looking dry-fix ridge could be unwelcome. The standard still applies to the way the ridge is held down, but how the tile is held and how the ridge looks are two questions, and the answer to the second may rest with the council.
If your house is listed, check with Stroud District Council's conservation team before you alter its ridge. Ridge details can count towards the special character that listed building consent protects, so ask before altering one. We explain which fixing we propose and photograph the existing ridge before any change.
What to ask when a ridge is quoted
Three questions go a long way. What are the ridge tiles bedded on, and what holds them down apart from that bed? Will the old mortar be removed back to a sound surface, or laid over the top? And does the quote show the fixings as part of the job?
Bedding and mechanical fixing together cost more than mortar alone, and on a short run that difference is small. Typical UK ranges from MyBuilder's 2026 guides reach £300 to £600 where ridge tiles are re-bedded or replaced, and £40 to £60 per metre for a dry ridge. They are national ranges rather than our prices, and your written quote follows a survey.
Whichever route suits the roof, bedded or dry, the fixing follows the standard, and our 10-year workmanship guarantee comes in writing. If the mortar is cracking, the reasons behind it are covered in why ridge mortar cracks and falls out. The hub page for this work is ridge, verge and dry-fix.