Cover Board Double End Corner White Cover Board Double Ended Corner 503mm (H) x 56mm (D) x 56mm (W) are used to cover the expansion gap that should be left at the junction of two cover boards at the corners of the eaves. As with all joints and corners, one side should be glued and one side sealed with silicon sealant. This trim should be cut to size with either a fine toothed saw or hacksaw.
