downpipe

Imagine a heavy rainstorm. Where does all that water rushing off your roof go? Often, it flows into a downpipe. A downpipe is a vertical pipe attached to gutters that carries rainwater from the roof down to the ground or into a drain. It helps protect a building from water damage. You'll often see one on houses, barns, and other buildings. In some places, people also call it a leader, a rain leader, or a downspout. The word can also mean a pipe that leads exhaust gases down from a car engine or turbo, but the rainwater meaning is the one most people mean.

A downpipe is usually the vertical pipe on a building that carries rainwater away from the roof and gutters. Think of it as the last part of the path the rain takes after the gutter collects it. The water runs down through the pipe and is sent safely to the ground, a drain, a soakaway, or a storage tank. Downpipes are often made of metal, such as aluminum or galvanized steel, but they can also be made of PVC plastic.

These pipes aren't just for houses; you'll find them on commercial buildings, sheds, and farm structures too. They connect directly to gutters, which collect rainwater from the roof surface. The size and number of downpipes needed depend on things like roof area and local rainfall. If a downpipe is blocked or damaged, gutters can overflow and water can collect near walls or foundations, which may lead to damp, leaks, mold, or other damage.

In another common use, especially in cars, a downpipe is part of the exhaust system. It is the pipe that carries exhaust gases down from the engine or turbocharger toward the rest of the exhaust. Even so, in everyday general English, people usually mean the rainwater pipe on the side of a building. It may not be the most noticeable part of a structure, but it does an important job quietly and well.