A verge refers to the junction between the roof and the gable end of the building.
A gable refers to the wall that infills between two opposite roof slopes and usually finishes in a triangular shape. The traditional way of finishing the roof at a gable wall is to use mortar.
Traditionally this detail includes a layer of plain tiles, slates or fibre cement board to assist in the weatherproofing. Unfortunately all too often this type of verge is poorly installed, leading to eventual water ingress.
When using dry fix systems the mortar joints between ridge tiles are replaced by plastic inserts, known as unions, that create the visual appearance of a mortar joint but have a hidden weather proofing system that carries away the water.
1. Remove the need for regular maintenance of the roof. Over time, mortar can succumb to frost damage and building movement. When this occurs, repairs can be quite costly as scaffold access is often required. By eliminating mortar from the roof you can virtually eliminate any such maintenance.
2. Allows the natural movement within a roof structure to take place without damaging the ridge and hip fixings.
3. Provide the means to 'mechanically' fix ridges and hip tiles, greatly reducing the risk of storm damage.
4. Provide discreet roof space ventilation at the ridge and hip which helps control harmful condensation in the roof space.
5. Allows the roofer to complete the work safe in the knowledge that rain will not cause mortar to stain the roof or frost to damage the mortar before it has had chance to properly set.