7 Types of Plumbing Used in Homes and How to Choose the Right One

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, including which ones play a role in transporting drinking water, sewage, and stormwater drainage, so you can choose the right one and know its purpose.

1. PEX Pipes

When it comes to types of plumbing pipes, 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. Without those joined elements, you have less risk of costly pipe leaks and line breaks. However, PEX is best suited for just hot and cold water supply lines.

Best used for: New residential homes

2. PVC Pipes

Most homes today have at least some PVC piping. PVC, or polyvinyl chloride, has been used since the 1950s. It’s a popular alternative to traditional steel or copper pipes because PVC pipes don’t rust, corrode, or degrade over time. PVC is also lighter, significantly less expensive, and easier to install, maintain, and repair than copper and steel pipes.

One major downside is that PVC is 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. 

Best used for: Waste drainage

3. CPVC Pipes

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. It also has non-corrosive properties and is easier to install than copper. 

In terms of drawbacks, CPVC isn’t recommended for outdoor use because it’s sensitive to UV rays. It can also become brittle over time, making it less stable than copper pipes. 

Best used for: Homes in need of repairs

4. ABS 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. ABS pipes are durable, budget-friendly, water-resistant, and corrosion-resistant, which is why you’ll find them in sewer systems, drains, and electrical insulation.

Like other plastic plumbing pipes, ABS is susceptible to UV rays, meaning it’s not meant for aboveground, exterior pipe systems. According to the U.S. Environmental Protection Agency (EPA), ABS also contains Bisphenol A (BPA), 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. 

Best used for: Underground drain pipes

5. Galvanized Steel Pipes

Galvanized steel has been used in homes for decades. This material is heavy-duty, which can be both beneficial and disadvantageous. It’s thicker and heavier than other commonly used pipes like PVC, ABS, and PEX, making it more durable. Galvanized steel is malleable, so it’s easier to manufacture and create custom piping for your home’s layout than cast iron. 

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 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.

Were used for: Drainage and venting in older homes

6. Cast-Iron Pipes

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. 

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. Also worth mentioning is that cast-iron pipes give off a metallic taste in tap water because of the iron rusting inside the pipe. 

Were used for: Sewage in older homes

7. Copper Pipes

Copper pipes are also very common in U.S. homes. They first appeared in the 1930s but gained popularity around 1960. Despite the high upfront cost of installing them, copper pipes have a long life span, won’t contaminate the water supply, and can handle high water temperatures, so they’re a good option for your home’s water lines. There are three types of copper pipes, L, K, and M, which differ in thickness. Most homes use type M for interior plumbing.  

Keep in mind that copper can corrode, especially at the joints where pipe segments meet and join soldered fixtures. If you have copper pipes and your water has a green or bluish hue, that can mean your pipes are corroding. 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.

Best used for: Hot and cold water

Choosing the Best Types of Plumbing Pipes for Your House

Understanding your plumbing system and, in particular, the different plumbing pipe types in your home can help keep the water flowing smoothly and safely, whenever and wherever you need it. 

It’s a good idea to 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 in 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 life span 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.

How Often Do Pipes Need to be Replaced?

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 life span of popular residential pipes is 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

Signs It’s Time to Replace Your Pipes 

Even if you perform meticulous maintenance, there may come a day when you need to replace a section of piping in your home. Pipes have a limited life span, and though PVC pipes can last 100 years, a material like PEX or ABS will generally last no more than 50 years.  Luckily, your pipes will give you a few warning signs.

• Constant Clogging: Weakened, rusted, or damaged pipes have rough edges that catch debris. In rarer cases, you may find that a tree root has grown through an outdoor pipe. Luckily, a plumber can typically cut out the damaged piping rather than replace the whole system. 

• Noise: Rattling, gurgling, hissing, vibrating, and banging noises are all signs that your pipes could be wearing down. This may be from built-up debris moving through the pipes, loose pipes from worn-out fittings, or water pressure issues. Leaks can also create noisy pockets of air called airlocks. 

• Water Pressure Issues: Low water pressure can point to a leak, corrosion, or repeated clogs that require a pipe replacement. High water pressure, on the other hand, can prematurely wear out pipes and cause leaks, burst pipes, and broken appliances.

• Discolored Water: This signals an issue with either the water main or plumbing inside your home. If a main breaks, it will stir up sediment, which should eventually clear when the city fixes the problem. If the issue stems from corrosion within your pipes, you may need to replace them. If you notice any signs that your pipes are failing, call a local plumbing repair service. Plumbing issues can compound, and a small leak repair is generally more affordable than the cost of burst pipe repair.