RIDGES Usage of recommended accessories leads to enhanced life of Roofs and Walls. Poor and substandard quality of accessories may adversely affect the superior quality of cladding sheets leading to reduced life. Accessories and the cladding material should have similar life expectancies as that of the main structure and hence criteria for selecting the accessories such as Ridges, Gutters, Fasteners and Flashings must be based on the design life of the structure.