Dry ridge and dry verge in Crowland

A familiar pattern on Crowland roofs goes like this. The ridge is re-bedded, it holds for a while, and then the mortar starts cracking again. That is not bad luck or bad workmanship. It is what happens when a rigid bed of mortar sits along the most exposed line of a roof, out on open fen with nothing to slow the wind down.

When re-bedding stops making sense

• The ridge has been re-bedded before and the mortar is cracking again
• Streaks and crumbs of mortar running down the tiles below the ridge
• Gaps opening between the verge tiles and the gable wall
• Birds getting into the open ends along the verge

What a dry system is

Dry ridge holds each ridge tile down mechanically, with screws, clips and a weatherproof roll along the top of the roof in place of the mortar bed. Dry verge does the same job at the gable ends: interlocking caps fixed over the tile edges, closing the gap that wind and birds get into. Nothing in the detail is rigid, so nothing cracks when the roof flexes in a gale.

Why the gable matters as much as the ridge

On a house facing open fields, the gable end often takes the wind side on. Mortar verges along that edge loosen first, the edge tiles start to lift, and once the wind is under one it works along the row. On plenty of Crowland roofs the verge is the more urgent half of the job, and if that is true of yours we will say so.

Explained before it is fitted

When a customer asked us about dry ridge and dry verge, we explained how the system works and why it suited their roof before fitting anything, and every job starts that way. We photograph your ridge and verges as they are now, go through the pictures with you, and put the price in writing. On older pantile roofs near the abbey we talk through how the caps will look before anything is ordered. The work is guaranteed for five or ten years depending on the job. Call 01733 855167.