flashing

Like any house, tin box has a number of holes in the roof to allow plumbing and mechanical vents to draw noxious, humid or lint-filled air out of the building. Each of these penetrations provides an opportunity for rainwater and critters to come inside, and so we need to use flashing to provide water-tight seals around the vents. All but one of the vents (the plumbing vent shown here) are protected by the overhang of the upper roof, which provides a comforting redundancy. The vent pipes are flashed with Dektite pipe boots, which adjust to fit a wide range of pipes, and which have a flexible base to accommodate different roof types. The pipe boots are held in place by mechanical fasteners and made watertight with a bead of sealant.