Corodrain valley troughs and gutters can be used with almost any form of slate, clay or concrete tiles. They provide an economic and durable alternative to lead. Provides weatherproof protection between a sloping roof and a vertical abutment. 25mm wide sanded strip for mortar adhesion. Two water bars in the horizontal section prevent moisture entering the roofspace. Properties Length: 3m. Width: 180mm. Height: 100mm. Profile: 1.3mm.