The Importance of Residential Plumbing

Your home’s plumbing is complex and relies on several pipes to remove fresh water and drain wastewater. Residential plumbers fix all sorts of problems, from clogged drains to leaking water lines. Click to learn more.

Every fixture in your home is connected to its drain line, which intersects with the sewer line and septic tank. These systems do not depend on pressure; gravity pulls waste matter downward into the drainage system.


Whether your toilets flush, your faucets turn on, or your showers run, your house depends on a residential plumbing system to bring and drain water in. The pipes in this system are usually buried underground or inside walls, but they’re essential for providing safe drinking water and disposing of wastewater. These pipes also keep pressure from building up in your home and protect against leaks.

The water supply pipe system routes municipal water into the house and delivers it to sinks, tubs, and toilets. It can include a water meter and shut-off valves that allow you to control how much water your home consumes. The system may also have a water heater or storage tank for hot water.

Indirect water supply systems can be used if the main water line is not close to homes or the water pressure is low. In this case, a pump may convey water to the water heater, which then distributes it to houses via the main or branch lines.

Water-using appliances like dishwashers and washing machines must be connected to the plumbing system to send wastewater away through the sewer system. The drainage system includes drain traps that prevent foul gases from entering the house and ensure wastewater is properly disposed of. It also consists of the waste pipes that carry sewage and wastewater to the city’s or county’s wastewater treatment plant.

When installing plumbing, using the right pipe materials and following proper sizing standards is important. More than properly sized pipes can cause damage and lead to costly repairs. A plumbing professional can help you choose the right pipes for your home.

There are two main plumbing systems for residential buildings: the water supply system and the drain-waste-vent (DWV) system. The water supply system brings clean water into the house and connects to sinks, toilets, and other fixtures. The DWV system sends wastewater from the house into the sewer or septic system. These systems must be designed to handle high volumes of pressurized water at various temperatures.

Many people don’t think about their plumbing system unless something goes wrong with it. However, the residential plumbing system serves two important purposes: supplying water for consumption and eliminating waste. It consists of hot & cold water supply pipes, fixtures, drain pipes, traps, valves, vent pipes, and a water storage tank.

Each home fixture has a drain directing wastewater into the sewer. Each fixture drain has a p-trap that keeps out the debris, such as food scraps, that might otherwise enter the drainage system. The drain also has a stub-out pipe that connects to the house drain line. These lines often run underneath the floor of a room, but they can also be hidden inside walls and in the ceiling.

These drain lines connect to a soil stack leading to the main sewer line, typically located in the basement or cellar. It is a metal pipe, usually cast iron or galvanized steel, extending to the municipal sewer or septic system. Occasionally, tree roots will work their way into these drain lines, causing wastewater to back up into the house. A plumber can auger the main drain line to clear out these obstructions.

When a toilet, tub, or shower is used, the drain opens to let the water flow away and then closes to prevent sewer gases from escaping into the room. The drain also has a flood rim level that indicates the point at which a fixture might overflow if it is not manually reopened. Some fixtures, such as pedestal sinks and freestanding bathtubs, are equipped with an overflow pipe that bypasses the regular drain when it becomes clogged.

Some fixtures, such as water closets and urinals, require a vent to keep the air from becoming too saturated with sewer gases. A vent line runs from the drain to a vent stack located in a wall or on the roof, and the code requires that it be properly sized to maintain negative pressure in the vent system at all times. For fixtures close enough to share a vent, a vent pipe can be used instead of a separate vent pipe.

The main drain line is one of the most important elements of a residential plumbing system. This large buried pipe transports household wastewater to the city sewer line or septic tank. Think of it like a sewer highway, with secondary drains from sinks, toilets, and tubs lining up as the local branches. When the main line clogs, it can cause problems throughout your house.

Knowing the difference between a sewer line and a drain line is essential so you can recognize when there is a problem and which type of plumber to call. A drain line is located inside your home, and you can usually tell if there is a problem by looking for signs of a clogged sink or bathtub. A clogged drain is typically something that a licensed residential plumber can fix.

If you have one, a sewer line is located outside of your home and is connected to the city’s sewer system or septic tank. The line is buried underground, so it is not as easy to see as the drain lines in your home. A clogged sewer line can be a huge problem and may require the help of a municipal plumbing company.

The best way to avoid a clogged main line is to keep tree roots away from it. Regular maintenance and a cleanout can also prevent issues down the road. All good residential plumbers will test the main line to ensure no backup.

In the case of a main line clog, you can tell it is occurring by looking for signs of sewage backup or a noticeable smell in the lowest part of your home. A clogged main line can affect multiple drains and rooms, so it is important to call a professional when you notice the symptoms.

If you are still determining where your main line is, you can always call the city, and they will provide you with a map of your property. All homes should have a cleanout for the main line; you can find this either in your basement or the lowest point of your yard. The cleanout should be opened and closed annually to ensure proper drainage.