What it is for
The ridge caps the line where the two slopes of a roof meet, and its tiles must stay put in wind and keep rain out of the gap below. In a dry ridge every tile is screwed or clipped down, so nothing depends on sand and cement keeping its grip.
The change came through BS 5534, the British Standard for slating and tiling. BSI's listing says mortar's tensile strength can no longer be counted on to stop wind lifting tiles, and Marley explains that from the 2014 revision onwards, bedded tiles and fittings need a mechanical fixing too. Many dry fix kits also vent the roof space at the apex, Marley notes.
Where you will see it around Barnsley
BSI's figure is that over half of all new and refurbished UK roofs use dry fixed ridges and hips. Around the borough they appear on newer estates and recently re-tiled houses, while many older terraces and semis keep mortar-bedded ridges.
From the pavement there is no band of grey mortar under the tile edges, just small union pieces where tiles meet and a cap at each gable end. In the loft the batten may show on metal brackets.
Heritage roofs follow different rules. In Elsecar, whose rows of houses were built for workers at the colliery and ironworks, Barnsley Council's conservation guidance calls dry-fix verges and ridge tiles visually inappropriate and says they should not be used. It wants stone slate repaired in matching sandstone, with ridge tiles bedded on mortar. Penistone, Thurlstone, Cawthorne and Hoylandswaine are among the borough's 18 conservation areas, so ask the council before changing a ridge in any of them.
Types and materials
| Part or kit | What it does |
|---|---|
| Brackets and ridge batten | Brackets on the rafters carry a timber batten along the apex, and each ridge tile is screwed into it (Marley). |
| Ridge roll | A flexible strip along the apex, its butyl edges pressed onto the tiles. On Marley's RidgeFast, joints lap by 100 mm and the roll is fixed to the batten roughly every 2 m. |
| Vented ridge | The roll also lets air out. RidgeFast needs an unbroken gap of at least 5 mm left at the apex. |
| Unions and clamps | Joining pieces that hold each pair of ridge tiles together. |
| Mortar plus mechanical fixing | A bedded ridge with a fixing kit that meets BS 5534, for example Marley's Mortar Bedded Security Ridge. It is not dry. |
Kits are made to BS 8612:2018, the specification BSI issued in January 2018, which tests how well they hold tiles, keep water out and last.
How it fails and the signs
Without mortar, the usual ridge fault goes away. Marley says mortar joints crack and weather, more so where a building moves, and that mortar can drop out or stain the tiles below.
Dry kits can go wrong too. BSI notes that some caused serious trouble with tiles working loose and water getting in, partly why BS 8612 was written. Look from the street, the garden or an upstairs window for:
- one ridge tile riding higher or sitting crooked against the rest;
- a gap between tiles where a union has gone;
- the roll peeling up off the tiles;
- water marks on the ridge timber, seen from the loft.
In a gale a loose ridge tile can be thrown off, and an open joint lets rain onto the roof timbers. See our guide to storm damage and insurance claims.
Repair or replace
Refitting a lifted tile or lost union is quick. For one replacement ridge tile, Which? found £80 to £300 including labour and materials, before VAT, when it surveyed 11 of its Trusted Traders in November 2025.
To convert a mortar ridge, the tiles are lifted and the old bedding cleared, then the new batten goes up on its brackets with the roll laid over it before each tile is fixed back. BS 5534 also covers repair work, BSI says, so a re-bedded ridge should be mechanically fixed. Marley says mortar will only cure in dry weather between 5°C and 25°C, whereas a dry kit can be fitted whenever conditions are safe.
Our BS 5534 guide sets out the rules, the ridge, hip and verge service page describes the job, and whole-roof prices are in our Barnsley new roof cost guide.
At a glance
- Other names
- Dry fix ridge, dry-fix system 3
- Code of practice
- BS 5534:2014+A2:2018, which no longer relies on mortar to hold tiles against wind 1
- Product standard
- BS 8612:2018, published 31 January 2018 2
- How common
- Over half of new and refurbished UK roofs, says BSI 2
- Apex vent gap
- At least 5 mm, continuous, on Marley RidgeFast 4
- Fitting weather
- Dry kits in most safe conditions; mortar only when dry and between 5°C and 25°C 3
- Elsecar conservation area
- Barnsley Council guidance says dry-fix ridge tiles should not be used 5
Take a photo from the ground, a window or the loft and send it on WhatsApp. We will tell you what it is and whether it needs a visit. Quotes are free and itemised.
Sources
- BSI, BS 5534:2014+A2:2018 Slating and tiling for pitched roofs and vertical cladding. Code of practice (published 28 February 2018)
- BSI, BS 8612:2018 Dry fixed ridge, hip, and verge systems for slating and tiling. Specification
- Marley, Dry fix or mortar for ridge and hip tiles (updated 27 February 2026)
- Marley, How to fix ridge tiles to a roof
- Barnsley Council, Supplementary Planning Document: Elsecar Conservation Area Best Practice, Design and Maintenance (adopted 2019), paras 7 and 10.2
- Barnsley Council, Conservation areas
- Which?, How much do roofers cost? (survey of 11 Which? Trusted Traders, November 2025)
General information about roofing in England, checked against the sources above when published. It is not a substitute for advice about your own roof.
