Self leveling white butyl rubber sealant. Use this sealant to install all ICON external Skylight domes. Standard 10 oz. Caulk tube. Mechanical fastening (screws) is required in conjunction with this sealant.
Instructions: Run a thick bead around the skylight opening. Place the skylight. Install screws. DO NOT overtighten. Run another bead around the edge of the flange, bringing a loop up over each screwhead.