Plumbing Basics Guide for Homeowners
For many homeowners, the plumbing system can be a mystery with a lot of hidden perils. Since most of the pipes and connections hide behind fixtures, walls, or even underground, people may not get a chance to see how they work until they need to. However, learning the basics around the plumbing system is important for homeowners, especially if they want to perform DIY maintenance, repair, or upgrades. By exploring the system and learning the most common mistakes, people will better understand what they are looking at and how they can minimize the risk of damage.
Table of Contents
- Plumbing System Basics
- DIY Plumbing
- Types of Pipes Used in Home Plumbing
- Types of Fittings Used in Home Plumbing
- Types of Valves Used in Home Plumbing
- Improve Home Maintenance Ability by Knowing Your Plumbing
- Further Reading
Plumbing System Basics
Since most of the home's plumbing is out of sight, homeowners might not know what is involved. This can make it more challenging to determine how to repair any issues. By looking at the various parts of the system, people can better understand the different functions of home plumbing.
Parts of the Home Plumbing System
Although homeowners may have a rough sense of how their plumbing is supposed to work, they may not know all the parts of the system. For example, when someone turns on a tap, they may not understand how the water arrives or what happens after it goes down the drain. People should familiarize themselves with various terms related to plumbing, including:
- Pipes: Tubes allowing the free flow of water, usually made of metal or PVC
- Fittings: Connectors that enable pipes to change direction
- Valves: Parts that control the direction and flow of water
- Fixtures: Permanent pieces that hold or control water, like sinks or tubs
- Traps: Special bends in the plumbing to prevent sewer gases from escaping
- Filters: Devices to prevent certain kinds of waste from accumulating in the pipes
- Appliances: Equipment that uses water, such as a dishwasher or water heater
There's a unique system to supply hot and cold water to fixtures and appliances and a different one for drainage. The parts are often categorized by parts that handle water directly related to the house and parts associated with the local water supply or waste management system.
Supply: How Homes Get Water
Most homeowners get their water supply from a municipal plumbing system. Others rely on well water, which must be pumped from a nearby well. In order to have access to water, homeowners must install a supply line underground. This line usually has a main shut-off valve and a specific amount of water pressure. From there, the supply line goes to the water heater for heating. The rest of the house has two supply lines: one for cold water and one for hot water. They often run together to each fixture and appliance.
Draining: Where Used Water Goes
Every fixture and appliance has a drainage system that connects to the home's drainage line. Certain rooms may also have a drain in the middle of the floor, in case of flooding or for cleaning. Each fixture has a trap that allows water and waste to pass through but doesn't allow sewer gases to return in the opposite direction. The pipes connecting the fixtures and the appliances connect to a branch pipe and eventually to a drain stack, which leads to the home's main drain line underground. That line connects to a septic system or to the municipal sewer system.
Venting: What Keeps Home Plumbing Running Smoothly
The decomposition of human waste can produce gases, which need proper venting in the home's plumbing system. Drain traps prevent the gases from pushing through the drain and into the home, but they don't provide ventilation. Ventilation is important because the accumulation of gases can cause glugging and slow the flow of wastewater out of the home's plumbing system. There are different types of vents that homeowners can consider. Most of the time, the vents connect to the vertical drain stacks and allow the gases to escape through a pipe leading directly to the roof.
Adding or updating the plumbing in the home is a popular DIY project. Homeowners should understand what they are doing in advance of working. By researching plumbing codes and avoiding common mistakes, DIY plumbers have a better chance of completing the project successfully.
Know Local Plumbing Codes
Before starting a project, homeowners should investigate the plumbing codes required in their area. There's a national plumbing code, but some regions may have additional requirements. Plumbing codes cover a variety of aspects of the plumbing system, and people should confirm that they are paying attention to each one. If homeowners fail to install plumbing to code, it may not pass an inspection. Common code violations include:
- Failing to properly install drain traps, leading to leaks or escaped sewer gases
- Improper material choices, such as rubber instead of copper or PVC
- Improper sizing of the pipes, which generally need to be larger as the drain line flows to the sewer system
- Failing to install pipes with the proper slope
- Placing fixtures too close together, particularly surrounding the toilet
- Weakening joists by running pipes through them without increasing support
Homeowners can minimize the risk of code violations by doing the research in advance and purchasing the correct materials and fittings. Increasing structural support reduces problems related to running pipes through the framing. Using purple primer makes it easy for inspectors to establish that a sealant was used.
Common DIY Plumbing Mistakes
DIY plumbing is not typically an easy job for homeowners. During the process, there are many opportunities to make mistakes that can lead to leaks, floods, or the necessity to replace materials and equipment. The most common errors that homeowners make while working on or replacing their plumbing are:
- Leaving burrs on cut pipes, which can decrease water pressure and weaken the pipe prematurely
- Failing to clean copper pipes before installing
- Using lead solder on pipes providing fresh water
- Bending pipes instead of using proper fittings
- Failing to secure the pipes at a regular interval so that they don't bend or collapse
- Not using glue, tape, or other appropriate types of sealant around fittings
- Mixing different types of plumbing materials without adding protection against corrosion
Many of these problems arise when homeowners don't realize the impact of their choices. For example, replacing one type of metal pipe with another type of metal can trigger a reaction. In this case, the homeowner would need to supply a divider between the two kinds of metal or replace the entire line.
Tools for DIY Plumbing
There are a variety of tools that homeowners can use for DIY plumbing projects. Some are related specifically to installation or repair, while others are typically used for general maintenance. Popular tools include:
- Pipe wrench
- Adjustable wrench
- Sink wrench
- Plumbers putty
- Plumbers tape
- Hand auger
For people planning to install new pipes, a pipe cutter or hacksaw may be necessary. In some cases, a wire brush or file can be ideal for removing burrs and cleaning out the inside of the pipe before installation.
Installing New Water Lines in a Home
Installing new water lines takes additional care, especially if people are only replacing parts of the line. As a general rule, experts recommend that homeowners consider starting with copper piping to run from the water main to the water heater. This part of the line usually requires a pipe that's three-quarters of an inch in diameter. If a copper pipe must connect to a galvanized steel pipe, place a rubber washer in-between. This will stop the pipes from reacting with each other.
From the water heater, people can use half-inch pipes to lead to various fixtures and appliances. They might choose from a variety of materials, like PEX or copper. For each step of the process, homeowners may want to test out the length with a dry fit. This term describes fitting the pipes together to confirm that they are the right size before applying glue, tape, or solder. The best approach to connecting the pipes depends on the material. People should investigate suitable connectors, especially if they are going to use multiple different materials together.
Types of Pipes Used in Home Plumbing
Homeowners have a few different types of materials that they can consider for plumbing. Copper, PEX, and PVC are the most popular, but there are a few others that people may want to research as well. Each one has benefits and drawbacks to research.
Copper Pipes: the "Gold" Standard
Copper is a highly durable plumbing material that has been popular for many decades. The material comes in a variety of widths and lengths that homeowners can cut easily to suit a variety of plumbing purposes. People who install copper pipes should generally use copper fittings and plan to solder or crimp them together. They may be able to use brass or PVC fittings, but they will need to take extra care to get a proper fit that will not corrode.
Although copper is a standard option for plumbing, it may not be preferable to homeowners for a few reasons. This metal tends to be more expensive, which can increase the total cost of the project. While copper is ideal in the case of fires, freezing can cause the pipes to burst. Highly acidic water can erode the pipe over time. Failing to use pipes of the proper thickness can lead to leaks, especially for pipes placed underground.
PEX Pipes: the DIYer's Dream
PEX is a type of flexible tubing that's fast becoming the industry standard for home plumbing. It's made out of a form of plastic with flexible mesh to prevent damage. PEX solves a lot of the problems that homeowners encounter with copper pipes. This material requires few connections, provided there's sufficient space for the tube to curve naturally. It expands and contracts, which makes it much less likely to freeze or burst. PEX is also cheaper than copper.
Given its flexibility, PEX comes in lengths ranging from 10 to 500 feet. The tubing comes in different colors to indicate hot water, cold water, or both. Homeowners may find it one of the easiest materials for a DIY project, assuming that they are able to purchase the special tools needed to install it. Although PEX is ideal for indoor plumbing, exposure to UV light breaks it down, making it inappropriate for outdoor projects.
PVC Pipes: Affordable, but Limited
PVC piping is a durable material with limited plumbing applications. It's a type of plastic that's molded into an inflexible shape. Because it's not bendable, homeowners will have to purchase fittings for it much as they would for copper pipes. PVC is often the least expensive option, and it's widely accessible in stores. People can usually find it in a variety of widths and moderate lengths for use indoors or outdoors.
PVC is relatively easy to install because homeowners can cut and connect it without soldering. People can also recycle it easily, making it a more sustainable option. It will not support high temperatures, making it inappropriate for hot water or drinking water. CPVC is made with a different process that supports temperatures up to 200 degrees Fahrenheit, but it does not last as long as regular PVC.
Other Types of Plumbing Pipes
Although copper, PEX, and PVC are the most common types of plumbing for the home, homeowners may encounter other materials as well. For example, galvanized steel was a prevalent plumbing material used for water supply lines through half of the 20th century. It fell out of favor because it corrodes easily. Similarly, cast iron was a practical material primarily used in drain stacks. Its weight and complication for maintenance made plastic options preferable.
Otherwise, homeowners may find a type of black plastic piping called ABS. Like PVC, people typically use ABS for drains and vents. It's similarly easy to purchase and install. ABS should not be confused with black polyethylene (PE) piping, which is a popular material used in drip irrigation systems. PE is sometimes used in indoor plumbing, but it's often not rated for it.
Types of Fittings Used in Home Plumbing
There are a variety of fittings that homeowners may encounter related to their plumbing. Some are easy to install, while others require special tools. Learning how to use each one correctly increases the likelihood that the plumbing will not leak or corrode.
Solder Fittings: Higher-Effort but Strong
Soldering a fitting may be the most complicated process in plumbing installation, but it produces solid connections. It's often used for copper pipes. Soldering requires:
- A propane torch
- Flux to hold the pipe in place
- Soldering material
The process of soldering or sweating a pipe involves using heat to raise the temperature enough that the soldering material will flow into the space between the pipe and the fitting. This provides a leak-proof connection.
Screw Fittings: DIY-Friendly
Screw fittings, sometimes called threaded fittings, use threads on a pipe and fitting to create a tight seal. With this type, it's crucial that homeowners choose the correct threading, whether it's male or female, or the pipes won't connect correctly. These fittings are some of the easiest for homeowners to DIY since they don't require special tools or equipment. For certain types of pipes or fixtures, people may want to use plumbers tape around the threads to prevent leaking.
Crimp Fittings: Great for Large Projects
Crimp fittings are a popular way for homeowners to connect pieces of PEX piping or avoid the need for soldering with copper. The crimp fitting is typically made of copper with a rubber interior. All plumbers have to do is slide the pipe into the fitting and use a crimping tool to provide a watertight seal. The crimping tool itself can cost a few hundred dollars, making it practical for a larger project but more expensive for minor repairs.
Push Fittings: Easy but Expensive
Push fittings are popular for DIY projects given their ease of use, but they can be some of the most expensive. With this type of footing, homeowners need only push the fitting onto the pipe. The connector clicks it into place and instantly creates a watertight seal. The connector is also easy to remove for maintenance and repair, making it a practical option for people doing a minor replacement.
Compression Fittings: Alternative to Solder
Compression fittings offer a handy alternative for homeowners who don't want to use soldering. They can handle high water pressure without popping off. With a compression fitting, people use a screw and a ferrule that, when compressed together, create a tight seal. It's not permanent like soldering, so it can be disconnected quickly. However, this can also increase the likelihood of leaking over time, especially if the pipe is flexible and moves.
Other Types of Plumbing Fittings
There are a variety of other fittings that homeowners may need to use in their home plumbing. These include:
- Clamp fittings
- Flare fittings
- Nipple fittings
Caps and plugs may be used to seal a tube at the end of the line. Otherwise, people may need special equipment or to hire a professional to install other types of fittings.
Types of Valves Used in Home Plumbing
Valves allow homeowners to control the flow of water and other fluids in the home. They are an essential part of home plumbing since they can prevent flooding, high water pressure, or backflow. Knowing the various types makes it easier for people to use them correctly.
Gate Valves: Used Frequently
Gate valves are some of the most commonly used in plumbing, although they aren't always the most practical. A gate valve uses a twist knob to raise or lower a metal gate inside the valve. The valve cannot be used to control water pressure, because that will increase the likelihood of leaking or breakage. Gate valves are becoming less popular because the interior parts can corrode and leak over time.
Globe Valves: Can Regulate Pressure
A globe valve, sometimes called a stop valve, looks a little like a gate valve. Globe valves got their name due to the round shape of earlier models, which have generally fallen out of use. With this valve, homeowners turn a knob to raise or lower a disk inside the valve. That movement can release water pressure fully, stop it entirely, or control the water pressure in-between. These valves are popular for use in outdoor faucets.
Ball Valves: Full Stop or Start
Ball valves are popular for use in lines where the water must be fully open or closed. A main water shut-off valve is a common application. The inside of the valve contains a hollow ball that's controlled by a lever on the outside. The lever turns the ball into position, either on or off. It does not offer partial flow, so it must be either fully on or completely off.
Butterfly Valves: Spinning Discs
Butterfly valves are similar to ball valves in that they use an interior mechanism to control the flow. A butterfly valve uses a disc inside. It's called a butterfly valve due to the fluttering movement of the disc as it rotates around a central axis. The exterior part of the valve may have a knob or wheel that homeowners can turn to release the flow of water. This valve goes from fully closed to fully open and vice-versa each quarter-turn, making it good for tight spaces. When the handle is parallel to the valve, it's closed, and when it's perpendicular, it's open.
Pressure Reducing Valves: Keep Pipes Safe
The plumbing inside a home is only rated to handle a certain amount of water pressure, which may call for a pressure-reducing valve. Sometimes called a pressure relief valve, this tool is designed to throttle the flow of water to prevent damage to the plumbing on the home side. They may be rated to a specific pressure limit and are more commonly used in homes where the municipal water supply has high water pressure.
Check Valves: Prevent Backflow
Check valves are relatively simple and are commonly used in any application where backflow would be a problem. They keep the water flowing in one direction, and they cannot be opened or closed. For example, homeowners may have check valves on their exterior hose bibs to keep water from flowing backward into the water supply line. People often have a backflow preventer, which is a type of check valve, on their sewer lines to prevent sewer backflow.
Needle Valves: High Precision
Needle valves offer a high degree of precision for homeowners who need to increase or decrease the flow by a very precise degree. The fine point of the needle sits in a stand until it's turned. Users may have to turn the knob several times to increase or decrease the flow, allowing them to tailor the consumption. It's more commonly used in cars but may also work well in gas pipes in the home.
Plug Valves: Multiple Full Stops
Plug valves are very similar to ball valves, but they have multiple possible applications. With a plug valve, there's a ball on the interior to open or shut water flow. Homeowners only need to turn the knob 90 degrees to open it. Unlike a ball valve, a plug valve can have multiple connections. It's popular for use in a main water shut-off valve, but it may also work for air and gas applications.
Improve Home Maintenance Ability by Knowing Your Plumbing
Understanding home plumbing can be a lifelong process for homeowners. Materials rise and fade in popularity, and the practical use of certain fittings may decrease in favor of newer approaches. For new homeowners, simply gaining greater knowledge about the system they have and how it works can decrease their chances of dealing with leaks or water damage. With the right tools and information, homeowners may even be able to perform basic DIY repairs or upgrades. By spending the time needed to know how the parts of the system work together and which ones are best for each application, homeowners can make a better, safer home.