Things You'll Need
Rubber boot kit
Chimney pipes on metal roofs must be flashed in order to create a watertight seal around the pipe and prevent leaks through the roof. The flashing can be installed quickly and easily with kits that use rubber pipe boots. The rubber boot is trimmed to fit around the pipe and then secured to the roof with screws and sealant. Rubber boot kits can be purchased online or at a roofing supply store for about $15. Installation takes about 15 minutes.
Trim the flashing in the center of the rubber boot with a roofing knife so it fits snugly around the pipe. Slide the rubber boot over the pipe to check the fit. Trace the outline of the base of the rubber boot onto the metal roof with a pencil. Remove the rubber boot.
Apply a generous bead of roofing sealant around the base of the pipe with the caulking gun. Add a bead of sealant on the traced line on the roof.
Slide the rubber boot over the pipe. Press firmly to seal.
Use the drill to secure the rubber boot flashing to the roof with 2-inch sheet-metal screws at 1-inch intervals.
Apply a bead of roofing sealant around the top and base of the rubber boot.