Why Ridge Mortar Fails in Reading
Standard sand-and-cement mortar on a ridge has a typical lifespan of 15–25 years before frost action and thermal cycling cause carbonation and cracking. On exposed ridge-line properties in Tilehurst and Caversham Heights — where south-westerly exposure is significantly greater than on valley-floor properties — mortar failure occurs faster. The 1930s semis along Tilehurst ridge and the Edwardian stock on Caversham Heights are the two most frequent sources of ridge repair calls we receive across Reading.
When mortar fails it typically fails in a predictable sequence: fine cracks appear first, then the joint opens, then individual tiles begin to rock on their bedding. The final stage is tile displacement — which is when the leak risk becomes active and the safety risk begins. Addressing ridges at the cracking stage costs significantly less than after displacement.
Mortar vs Dry-Fix Ridge Systems
Dry-fix ridge systems use mechanical clips and breathable underridge foam to secure tiles without mortar. They accommodate seasonal movement in the roof structure, are impervious to frost, and carry 25-year guarantees from manufacturers such as Redland and Marley. For any exposed position, exposed-hip roof, or property with a history of recurring ridge failures, conversion to dry-fix is the definitive long-term solution.
