Stage 02 · Exposure
Open ground, wind and fixings
With the cliff edge close by, wind reaches verges and ridges from every side, so how those edges are fixed matters more than the tile.
A cliff-top site has little to slow the wind before it hits the roof edge. The tiles in the middle of a slope hold each other down. The tiles at a verge, a ridge or a hip have nothing on one side, so they depend on whatever fixes them. That might be mortar, a clip, a screw, or a mix of all three laid down on different dates by different hands.
Is mortar still enough on a ridge or verge?
Marley's page on BS 5534, updated February 2026, reports that the 2014 revision stopped treating mortar as enough on its own for ridge and hip tiles: anything bedded should carry fixings too. Where a roof goes over to clipped caps in place of mortar, BS 8612 is the benchmark the system is tested against. Marley also points out that installing to BS 5534 is not a legal requirement, so a mortar-only ridge is neither an offence nor a defect in itself. On a site this open, though, we would propose fixings whenever a ridge is rebedded, and the decision stays with you. Rebedding without fixings leaves the weakest point of the roof where the wind is strongest.
Edge words, plainly
- Verge
- Sloping edge of a gable end
- Ridge
- Highest line, where slopes join
- Dry-fix
- Clipped caps instead of mortar
- Soffit
- Underside board beneath the eaves