Common plumbing pipes are galvanized steel, copper, ABS, PVC, CPVC, and PEX.
Galvanized steel and cast-iron pipes are rarely used in homes.
Many homeowners choose to replace copper pipes with PEX.
PVC pipes are best for drainage but pose environmental concerns.
A professional plumber can help determine the best type of pipe for your home.
Let’s be honest: When you lie in bed awake at night, chances are you’re not thinking about your plumbing pipes. Your home’s plumbing may be the last thing on your mind—until something goes wrong. That’s why it’s important to understand the various plumbing pipe types available for your home, so you can choose the right one and know what their purpose is.
Different Types of Plumbing Pipes and What They’re Used For
Understanding what kind of plumbing pipes are in your home can help you maintain your system and troubleshoot issues when they arise. So before you indulge in your next bubble bath, take some time to learn the types of pipes in your house and how they keep the water flowing.
In general, plumbing pipes are typically used to transport sewage, stormwater drainage, and drinking water. Some types of pipes work better than others depending on their function. Take a look at seven common plumbing pipe types, below.
1. PEX Pipes
Best used for: New residential homes
When it comes to common plumbing types, PEX, or cross-linked polyethylene, is the new kid on the block. Since its emergence in the late 1990s, it’s become a superhero in the residential plumbing world because of its affordability, durability, and functionality.
Unlike copper and steel, PEX doesn’t rust or corrode. In addition, PEX is packaged in a coiled tube, which means it can usually accommodate the twists and turns of your system without needing to be segmented, spliced, and joined. And without those joined elements, you have less risk of costly pipe leaks and line breaks.
PEX looks a lot like the hard plastic of PVC. Like PVC, it includes markings that show the pipes’ sizes and temperature ratings. PEX pipes can come in almost any color but are typically red and blue to indicate hot and cold water supplies.
Though PEX pipes may be a rockstar in plumbing, they’re not without limitations. PEX generally suits hot and cold water supply lines, while PVC works better for drain lines. Also, PEX is a pretty new technology, so homeowners don’t know exactly how long they will last or what unexpected drawbacks there may be. Unlike copper, steel, and PVC pipes, PEX hasn’t had time to build a reliable track record. And while it’s looking good so far, it will still take some time for PEX to prove itself as a viable pipe choice.
2. PVC Pipes
Best used for: Waste drainage
Most homes today have at least some PVC piping. PVC, or polyvinyl chloride, has been used since the 1950s.
It’s a very popular alternative to traditional steel or copper pipes because, unlike the latter, PVC pipes don’t rust, corrode, or degrade over time. You can glue PVC pipe as a DIY project for a budget-friendly repair. It’s also lighter, significantly less expensive, and generally easier to install, maintain, and repair than copper and steel pipes.
PVC pipes look like hard, white plastic with markings along the side. These markings indicate the pipe’s diameter and the temperature ratings for that particular grade of PVC piping. And that leads to the one significant downside of PVC: it’s generally not suitable for hot water supply lines. That means you’ll need to limit your use of PVC to waste drainage and allow copper or steel to do the hot water work.
Additionally, PVC outgassing poses a health and environmental concern. Over time, PVC releases volatile organic compounds (VOCs) into the air. Consider switching to copper or galvanized steel plumbing as an alternative to PVC if you’re concerned about outgassing.
3. CPVC Pipes
Best used for: Homes in need of repairs
Though chlorinated polyvinyl chloride (CPVC) looks similar to PVC piping, don’t let its name fool you. Like PVC, this material contains a flexible thermoplastic called polyvinyl chloride—only it’s chlorinated for added flexibility. CPVC has a much higher chlorine content, making it a superior choice over PVC.
In addition to its added flexibility and strength in comparison to PVC, CPVC pipes come with other benefits:
Faster to install and easier to replace than copper pipes
Longer-lasting than PVC while offering the same non-corrosive properties
Handles the demand of high water pressure, making it ideal for a main water supply line
Lightweight and flexible
Handles higher temperatures than PVC—up to 200 degrees Fahrenheit.
Available in various sizes
As with most choices, a few cons come into play when choosing CPVC for your pipes. These include:
UV sensitivity: CPVC breaks down when exposed to UV rays and shouldn’t be used in outdoor applications.
High thermal expansion: CPVC is not ideal for climates with many temperature changes, as it expands and shrinks quickly.
Brittle material: Over time, CPVC changes from ductile to brittle, making them less stable than copper pipes.
4. ABS Pipes
Best used for: Underground drain pipes
Acrylonitrile butadiene styrene (ABS) pipes are another plastic material for plumbing. The most obvious visual difference between ABS and PVC pipes is that ABS usually comes in black. You’ll find ABS pipes in sewer systems, drains, and electrical insulation.
ABS pipes are durable, budget-friendly, water-resistant, corrosion-resistant, and ideal for underground drain piping. They’re easier to install than metal and PVC pipes, as they’re lightweight and don’t require a primer to hold the material in place. This material uses cement that you don’t need to clamp down during installation.
Like other plastic pipes, ABS is susceptible to UV rays, meaning it’s not meant for above-ground, exterior pipe systems. According to the U.S. Environmental Protection Agency (EPA), ABS also contains Bisphenol A (BPA), which is a known toxin that can negatively impact the environment and may cause cancer. You should avoid using ABS pipes for drinking water for this reason.
5. Galvanized Steel Pipes
Were used for: Drainage and venting in older homes
Galvanized steel was used in homes for decades. This material is heavy-duty, which can be both beneficial and disadvantageous. Here’s what you need to know about galvanized steel pipes.
Galvanized steel pipes are a common pipe material for older homes. They’re thicker and heavier than other commonly used pipes like PVC, ABS, and PEX, making them more durable. Galvanized steel is malleable, making it easier to manufacture and create custom piping for your home’s layout than cast iron. It’s also rust-resistant.
Galvanized pipes have a metal layer coating designed to corrode before the pipe. But once the protective coating has ebbed away, the steel pipes may begin to rust. If you notice discoloration or particles in your water, this can be a good sign that your galvanized pipes are failing.
Because steel pipes tend to be heavier and more unwieldy than other types, they can also be more difficult to repair or replace. This issue can drive up the labor cost if you hire a local plumber to do the work. Plumbers may charge a flat fee per service or they may charge an hourly rate, generally ranging from $70 to $160 per hour. Telling your plumber your home has galvanized steel pipes can help you get a more accurate estimate on your service call.
6. Cast-Iron Pipes
Were used for: Sewage in older homes
Like galvanized steel pipes, cast iron pipes were commonly used in older houses—primarily for sewage systems. Today, however, they’ve mostly been replaced with PVC and other easier-to-install pipes.
Cast iron is very durable and often used in the automotive and cooking industries, where it can handle extremely high temperatures—hence the cast iron pan. You might find cast iron in homes and commercial or high-rise buildings for sewage and draining systems.
Cast iron pipes tend to be more brittle compared to other metals. While they’re typically corrosion-resistant, this is not the case for seawater. Iron will quickly corrode and pit from exposure to salty environments, so you’ll want to avoid installing this material in homes near saltwater. While cast iron handles high heat well, it falls short for high-pressure appliances and liquids.
Also worth mentioning is that cast iron pipes give off a metallic taste in your tap water because of the iron rusting inside the pipe. Over time, cast iron pipes tend to leak, as well. For these reasons, cast iron pipes are a no-go for home plumbing at main water lines.
7. Copper Pipes
Best used for: Hot and cold water
Copper pipes are also very common in U.S. homes. They first appeared in the 1930s but gained popularity around 1960.
Copper is lighter, thinner, and generally smaller in circumference than their steel counterparts. Of course, newer copper pipes have a signature reddish hue, but over time, oxidation can turn the pipes a green or dark brown color. Like steel, copper pipes are also very durable.
Copper can corrode, especially at the joints, where pipe segments meet and join soldered fixtures. If you have copper pipes and you find that your water has a green or bluish hue, that can mean your pipes are corroding.
If you have an older home, signs of corrosion in your copper pipes can pose a risk of lead contamination. Soldered elements in your pipes may contain small amounts of lead, leaching into your water once pipe corrosion begins. This corrosion can result in significant health hazards, particularly for young children.
If your copper pipes were installed after 1986, when the EPA banned the use of solder and other plumbing elements containing lead, then lead contamination shouldn’t be a concern. But copper, though it’s very durable and lighter than steel, is also very expensive. You’ll pay more for parts to replace copper piping or make repairs, but the tradeoff in longevity may be worth it.
Choosing the Best Type of Pipes for Plumbing in Your House
Understanding your plumbing system and, in particular, the kinds of pipes in your home can help keep the water flowing smoothly and safely, whenever and wherever you need it. Enlist the help of a local plumber to help you determine which pipes are your best option based on the following factors.
Your budget: The ease of installation, the size of your home, and required maintenance affect overall plumbing pipe costs.
Your water type: Depending on where you live, your water may be corrosive (like coastal areas).
Your local building codes: Always refer to your local plumbing codes to ensure you adhere to the municipality’s specific requirements for designing and amending a plumbing system.
Your exposure to sunlight: Ultraviolet (UV) rays deteriorate the quality of plastic pipes over time, decreasing their lifespan and quality.
Your soil characteristics: Soil with excess rocks, moisture, and other materials can degrade less durable pipes.
Your desired water pressure: Wide, durable pipes, such as plastic, are best for high water pressure.
Frequently Asked Questions
Polyvinyl chloride, or PVC, pipes are considered one of the best pipe types for drains and vent lines due to its low price point, lightweight material, corrosion resistance, and installation ease. But copper has long been considered the best piping option due to its durability, but for many homeowners, the price of copper can be cost-prohibitive.
The best type of piping for underground main water lines are PVC and PEX pipes because of their ability to be buried and withstand high levels of water pressure. PVC and PEX pipes are resistant to rusting and corrosion, which makes them ideal for transporting water. Copper is another efficient type of pipe for underground water lines, because of their resistance to rusting and leakage, but again, copper pipes are on the higher end of the price range.
Copper pipes are the safest type of pipe for carrying drinking water because they won't leach chemicals into your drinking water. However, for the best water quality, you should be sure to use copper pipes with lead-free joint material. The next best options for carrying drinking water are CPVC and PEX pipes.
If you use copper pipes for drinking water, you should be sure to check your water’s pH level. If it has a pH value lower than seven, you'll need to balance your water acidity with a purifier to avoid corrosion that could affect your drinking water quality.
You should replace your pipes as they approach the end of their typical life span, or if they are experiencing frequent leaks and problems. The typical life span of popular residential pipes are as follows:
PVC: At least 100 years
PEX: At least 50 years
CPVC: 50 to 75 years
ABS: About 50 years
Copper: 50 to 100 years
Galvanized steel: 40 to 100 years
Cast iron: 50 to 100 years