Household plumbing pipe seems invisible. You don't really see it--until it bursts in the basement or under a kitchen sink. Then you need to know something about pipe--and quickly! This guide tells you what you need to know about plumbing pipe. Refer to other plumbing guides for information on other aspects of your home's plumbing.

How Does It Work?

Plastic (PVC) pipe comes in a variety of types, sizes, and connections.

Household plumbing pipes are installed in walls and under floors during construction. They carry fresh water to kitchens, bathrooms, utility rooms, and so on. A separate system carries waste water from a sink or toilet to the main drain and out of the house to the sewer or septic system.

Pipe is available in cast-iron, brass, copper, galvanized steel, and plastic. Fittings are connections between pipes that allow pipes to turn or attach to a fixture such as a faucet or water heater.

How the fittings are installed on pipe depends on the material. For example, copper pipes are soldered together or joined with compression or flare fittings. Plastic pipes are joined with plastic screw-on fittings or PVC cement. In addition, transition fittings can be used to join plastic and metal pipes.

What Can Go Wrong?

Pipe doesn't move, nor is it subject to wear. So the greatest cause of pipe problems is age (pipes become brittle or corrode, fittings fail) or damage from freezing.

Fix-It Tip

Plumbing in your home was installed to follow local plumbing codes at the time the house was constructed. Before doing more than repairing existing pipe, check with local building departments to find out whether permits and inspections are required.