Plumbing is the process of installing, maintaining, and repairing the pipes and fixtures within a building. It is a vital part of any construction project. Plumbers work to make sure that buildings are safe and efficient while also ensuring that potable water is available. In addition, they ensure that waterborne wastes are removed from buildings.

Plumbing systems come in many shapes and sizes and are made up of two subsystems: one brings fresh water into the building and the other is responsible for wastewater removal. Water coming into a home is under pressure and flows through a meter, which registers how much water is being used. The main water shut-off valve is typically located near the meter, and it must be closed in the event of a plumbing emergency.

The sizing of a sanitary drain depends on the number of fixtures that will use the pipe. A minimum of four inches in diameter is generally recommended for a house drain. House drains can be made of a variety of materials, including cast iron, vitrified clay, plastic, and lead. For DWV systems, PVC and ABS are the most popular materials. Proper scouring action will keep solids from clogging the pipe.

Copper pipes come in four different wall thicknesses. Type DWV (thin wall) is the thinnest and typically used only for drain pipes, while types M and L are thicker.