How to Use Aluminum Screws on Steel Roof

Set the first piece of steel roofing in the corner of the roof so it is hanging 2 inches over the edge. Line up the first aluminum screw at the top of the panel in the flat area adjacent to the ribs of the roofing.

Put the aluminum screw in the drill bit and check to make sure the metal washer built into the screw is just underneath the head. Underneath the metal washer will be a rubber seal to help prevent leakage in the roof. Add a dab of silicone sealant on the threads of the aluminum screw to prevent galvanic interaction, which can lead to corrosion and the roof not sealing properly.

Drill the first screw into the roof until the head of the screw is level with the roof. Screw it in tight to the corrugated part of the roof to prevent water from getting to the lower part of the roof and creating a leak. Stop drilling when the washer is firmly set into the metal roof.

Line up the second screw on the next flat spot and add a dab of silicone sealant to it. Fasten it in the same manner and continue around the entire first piece of steel, making sure to stay on the corrugated part of the roof. Fasten down about 15 screws on the first piece, always making sure to add a little silicone sealant to the threads of each one.

Place the second piece right next to the first so it is overlapping by about 2 inches. Run a bead of caulk between the two sheets and install the second sheet in the same manner as the previous sheet. Continue the same way until all of the sheets have been installed on the roof.