plumbing covers many services, from installing and repairing faucets to sewer line repair. Understanding what makes up a plumbing system is important to recognize when something isn’t right.
The basic components of a plumbing system include water supply pipes, drain pipes, fixtures, and a wastewater system. Each of these elements works together to deliver clean water and remove waste.
Getting fresh water into the home and draining waste out are two of the most important functions of the plumbing system. It’s also one of the most complex, thanks to a network of pipes found behind walls, under floors, and in crawl spaces. Understanding the basics of residential plumbing can help you work with professionals to install, repair, and replace piping in your house.
A home’s water supply pipes bring in municipal or well water and direct it to faucets, showers, tubs, and other appliances. These lines typically run from the meter or other source through a water shut-off valve, often located close to the street connection. This valve is important, as a burst pipe could flood your entire house quickly if it’s not closed immediately.
Once inside your home, a main line from the city water supply splits into hot and cold water supply lines. These lines travel to each bathroom, kitchen, and other areas of the house where water is used. In some older places, these pipes also travel through the basement to deliver water for toilets and other fixtures. In newer homes, these supply lines are separated, meaning water usage in one part of the house doesn’t affect water availability in another.
The type of pipe used in these lines depends on several factors, including your budget, the size of your house, and the available water pressure. In general, copper pipes are more durable than other materials but are also more expensive. Plastic piping, such as PEX, has become increasingly popular among DIYers and pros because it’s lightweight and more flexible than other types of pipe. It also reduces installation costs by eliminating the need for multiple pipe connections.
Other plumbing pipe materials include steel and galvanized iron. These are cheaper and less durable than copper but can be used in some circumstances. However, these pipes should never be exposed to the elements as they can corrode over time and contaminate water with metal particles.
A drain pipe conveys waste from individual fixtures such as sinks, bathtubs, and toilets. These pipes must be sized properly for the institution, as overloading may cause blockage. A good rule of thumb is to have a pipe size one-half the fixture’s capacity. This way, the drain will empty when flushed but won’t overflow during normal use. The power of each institution is determined by a formula that factors in the type, frequency, and duration of use. This data is used to create a fixture unit (DFU) value, determining the maximum permissible load for the drainage system.
The sanitary drain or house sewer is the drainage pipe that transports the waste to the public or private sewer or individual sewage disposal system. It’s a minimum of 6 inches in diameter, and the material is usually cast iron, vitrified clay, or plastic. It’s also possible to find lead drain lines in older homes. A septic tank and system may require a separate line to carry the waste to the tank.
Most drain lines are connected to a stop valve that can be closed off in an emergency, such as a leak or clogged pipe. These are usually located in the basement, garage, or under a sink. The valves should be positioned so they can easily be accessible in the event of an emergency.
In addition to stops and drains, most homes have a plumbing venting system that prevents air from flowing into the drainage system. If this happens, it can bring stinky sewer gases into rooms. These are dangerous and should be avoided. Venting systems are usually a one-way valve and a vent tube, but they can be constructed of different materials depending on the installation.
The piping from a stop to the main water supply line is called a service line and should be buried at least 4 feet deep to prevent freezing. It’s recommended that this piping be made of PVC or PEX because it’s less susceptible to corrosion than other types of pipes. Copper is also still in use, but it’s becoming less common due to the higher cost and lower thermal efficiency compared to different piping types.
Your home’s drain pipes carry wastewater and other waste from your sinks, toilets, tubs, and showers. These drain lines connect to your main sewer line, dumping waste into your municipal sewer system or septic tank. If your house sewer line gets clogged, it could impact your home’s other drains and lead to sewage back-up and other unpleasant side effects.
Your house sewer line typically runs between 4 and 6 inches in diameter and stretches from your home’s foundation slab to the beginning of your city’s municipal sewer line. Depending on the age of your home, it may be made of cast iron, galvanized steel, or PVC plastic. PVC is the most common in-home drainage pipe material, praised for its versatility, durability, and blockage resistance. Other popular choices include ABS plastic and polyethylene crosslinked (PEX) piping.
Once your wastewater leaves the drain traps, it enters horizontal pipes called branch drain lines that slant downward to promote the easy flow of waste. After these drain lines, your wastewater drops into vertical pipes known as soil stacks. The tops of the soil stack pipes vent to let out harmful gases and help maintain balanced air pressure in the plumbing system.
After your wastewater exits the soil stack pipes, it drops into your main sewer line. This massive pipe carries all the waste from your house to your municipality’s sewer or septic system. A clog in your home’s main sewer line can affect all the other drains and toilets inside your house.
Contact a professional plumber immediately if you suspect a problem with your household’s main sewer line. Since these pipes run beneath the ground, they require special equipment and extensive plumbing knowledge to repair. A professional plumber can usually give you an over-the-phone estimate on the service cost before coming out to your home. This will help you avoid any unnecessary expenses. A professional plumber can also install a new sewer line cleanout for you.
Water is a crucial component of everyday life. However, the pipes that bring it into your home and carry away wastewater can become a source of major problems if they need to be properly maintained and fixed when needed. Water service lines connect a house to the city’s water main and sewer lines, while sewer lines carry waste from the home’s toilets, sinks, and floor drains to a municipal waste treatment plant. The homeowner is responsible for maintaining and repairing the water service line and the sewer pipes. Any break, clog, or leak in these lines can lead to thousands of dollars in damage.
When installing residential plumbing, plumbers start by mapping out the piping layout. Then, they dig trenches to lay the pipe. While applying the pipes, plumbers look for buried gas and electrical lines to avoid conflicting with them. Once the piping is laid, it’s time to install the fixtures. Plumbers use a combination of flexible tubing and hard-wearing metals, including polymer (plastic) materials such as crosslinked polyethylene and high-density polyethylene, to create water supply lines. These are more durable than soft copper and easier to assemble.
After installation, the plumber turns on the water to test it for leaks or other issues. This includes turning on every faucet to ensure it works correctly. The plumber may also turn on the sprinkler system to check for leaks in the irrigation piping. Once everything works as it should, the plumber will close the main water shut-off valve, usually located near the meter. This allows them to shut off the water quickly in an emergency.
The section of the water line that runs from the curb stop to your house is known as a water service line. Water utilities often have records noting the material of the portion of a water line that’s under public property, but these are typically sparse or nonexistent for private parts.
If you suspect a problem with your water line, it’s best to contact your local water utility for information on the material and age of your line. You can also visually inspect your line for a lime buildup, indicating that it’s made of galvanized steel or cast iron. If you’re unsure about the material of your service line, you can test it for lead. A lead service line will appear silvery-gray, shine when lightly scratched, and won’t stick to a magnet.