Velux Curb Mounted Skylights Designed to be used where a site-built curb is the preferred method of installation, curb mounted skylights consist of an insulating glass lens sealed into a protective metal frame designed to mount on top of a site-built curb. Velux flashing is installed around the site-built curb, then the skylight is mounted onto the flashed curb and fastened into place. Blinds and controls are available.