Chimneys should extend at least 2 feet higher than any portion of a building within 10 feet, but not less than 3 feet above the highest point where the chimney passes through the roof. This is known a the 3-2-10 Rule for Chimneys.

A common vent is one vent that serves more than one fixture, functioning as an individual vent for each fixture. Wet venting is venting single or double bathroom groups or combinations thereof, where one vent pipe may serve all the fixtures connected to the wet vent. Waste-stack venting is venting individual fixtures through a drainage stack, and the over-sized stack functions as the vent. Circuit venting is venting up to eight fixtures with a single vent pipe. A combination drain-and-vent system is restricted to floor drains, sinks and lavatories, and relies on the over-sized drain pipe. Island-fixture venting has a vent installed below the flood-level rim of the fixture before rising to connect to another vent.

Plumbing Vents

Depending on location, there are primarily two different types of plumbing vent flashing. The most common in northern climates is the neoprene or metal boot. In Florida and in many other southern states, a lead flashing, which also protects the plastic vent pipe from ultraviolet damage, is more common. The stack vent is provided for the waste stack. The stack vent is the extension of a soil or waste stack above the highest horizontal drain that is connected to the stack. This is the main commonly-observed pipe that is observed penetrating the sloped roof surface, and it may also be visible in the unfinished attic space. This is an inspection image of a stack vent pipe penetrating the roof covering surface.

Valleys are weak spots in roofing systems. They have a lesser slope than the adjacent roof planes. They erode faster because water is directed into them. Inspectors must look not only at visible flashing, but also at the adjacent roof covering, at least a couple of feet on either side.