Everything to Know About Bathtub Plumbing
The average person uses their bathtub every day, but it's not often anyone thinks about them beyond the daily cleaning and regular maintenance. Everyone expects their bathtub to work as expected every time, but how exactly does plumbing allow for that daily bath?
The Basics of a Home Plumbing System
The plumbing system requires three important components: gravity, pressure and, of course, water. Plumbing systems are composed of two separate subsystems: a supply system for freshwater in, and a drainage system for wastewater out. The two work together to ensure that all appliances in the home function seamlessly.
The supply system that brings water into a house is highly pressurized to carry water to upper levels and around corners with ease. As water is pulled into a home, a meter reads the amount used, which is very important when determining usage. In case of emergencies, such as a burst pipe, there are shut off valves near the meter. Some home fixtures, such as tubs or toilets, have individual shut off valves, which is helpful when localizing the cause of the issue to help avoid shutting off all of the water. For hot water supply, the pipe in the system carries it to the water heater before going to appliances or fixtures.
The drainage system which carries wastewater out of a house is not pressurized. Rather, it relies on gravity and features to provide air supply such as vents and traps. Every fixture has a trap to ensure that wastewater leaves the home and there isn't a backup. This is referred to as the drain-waste-vent system.
How Exactly Does Bathroom Plumbing Work?
Bathrooms have several fixtures that require specific plumbing. All full bathrooms have a shower or bathtub (or both), a toilet and a sink. The hot water line is connected to the bathtub and the sink, while the toilet does not need a hot water pipe. All of these fixtures act as bridges between the supply and drainage systems, as described above. 
While the toilet has a built-in trap, the tub and the sink have the traps added into the piping to ensure no backups. All three of these fixtures connect to the same drainage pipe and are brought to the vertical soil stack. The soil stack has a sack vent to ensure airflow is appropriate to expel the waste out of the house.
Bathtub Specific Plumbing You Should Know
The bathtub is a very important fixture in a bathroom and comes in either freestanding or drop-in models. While the hot and cold water supply lines bring the water to the tub, the diverter pipe centralizes or diverts water flow and allows for appropriate temperature and pressure water flow. There is also a shut-off valve for quick localized water shut-off if emergencies occur. An overflow pipe is also included to drain excess water if it reaches a certain level.
When draining the water, there is a drainage pipe with a trap to prevent back up into a tub made of either brass, PVC or ABS (acrylonitrile butadiene styrene). A stopper can usually be switched on or off to regulate the water drainage. When the water from the drain goes through the trap, it travels to the soil stack and leaves the house.
About The Super Plumber
The Super Plumber has been providing expert bathroom remodeling services in Victoria, BC for over 14 years. They have been expanding their services every year and are focused on providing consistent, high quality plumbing solutions.
