The majority of older houses with gable roofs have wet verge roofing. The wall above the area where two verges in a roof meet is called the gable end, and the verge means the outer ends of your roof above the gable end. Mortar was used traditionally to fix these areas of the roof. The benefits of using mortar included preventing water ingress and potential pests (such as birds) from nesting in your roof. Roofs, which use mortar to fix the edges, are called “wet verge” roofs.