Home plumbing systems are some of the most confusing and intimidating for DIYers to work on, partly because there are many different types of plumbing pipes. Whether you’re diagnosing an issue in your home, implementing a solution, or running plumbing to a new room or fixture, you must understand the different kinds of pipes and their applications.
This guide discusses the seven types of plumbing pipes you might find in or need for your home. We’ll break down the cost of each, discuss the pros and cons of the different styles, and include some additional information about pipe measurement and selection to help your project go as smoothly as possible.
- Different plumbing pipes suit different applications, so you should choose the one that works for your specific purposes.
- Not all plumbing pipe materials are up to building code in all areas, so make sure you check the legality of an option before purchasing and installing.
- Your water quality can often influence which type of plumbing pipe suits your home, so it’s a good idea to check acidity and hardness before installing a specific material.
What Are the Different Types of Plumbing Pipes You’ll Find Around Your House?
You might find seven main types of plumbing pipes throughout your home. Identifying pipes before you begin any DIY projects and knowing which pipes are suitable for different applications are crucial. The table below includes a quick look at the seven kinds of piping you might run into, the most common application of each, and the average cost per linear foot.
|Type of Plumbing Pipe||Best Used For||Average Cost (estimate per linear foot)||Read More|
|Rigid Copper Pipe||Hot and cold water supply lines||$2.50 – $10||Jump to section|
|PEX Pipe||Hot and cold water supply lines||$0.50 – $2||Jump to section|
|PVC Pipe||Cold supply lines (CPVC pipe only) and drain lines||$0.50 – $2||Jump to section|
|ABS Pipe||Drain and vent lines||$0.50 – $5||Jump to section|
|Flexi Pipe||Short connections to fixtures||$5 – $20 (unit cost)||Jump to section|
|Galvanized Steel and Cast Iron||Hot and cold water supply lines (outdated), drain lines and main waste lines, and vent lines (outdated)||$2 – $25||Jump to section|
|Black Pipe||Natural gas supply lines||$0.50 – $3||Jump to section|
1. Copper Pipe
Best for: Copper pipe is best for water supply lines, and that’s typically the only application you’ll see them used for in your home. These pipes can deliver water from your water main to all of your plumbing fixtures and appliances, like your water heater and water softener.
Average cost: Copper pipe can range from around $2.50 to $10 per linear foot, depending on the pipe walls’ thickness and the pipe’s diameter. You’ll most commonly see Type L ½-inch copper pipe behind your walls and running to your quick disconnects (speedy valves) behind your fixtures. This size pipe usually averages around $3 per linear foot.
Copper pipe is made primarily of copper, as the name suggests, so it has a shiny copper color. It’s technically a copper alloy that also contains silver and phosphorus. It comes in long sections for running lines behind walls and several joints for 90-degree angles, T connections, and more.
There are three types of copper pipe: L, M, and K. The different letters refer to different wall thicknesses. Type L is the most common for residential supply lines.
Pros of Copper Pipe
There are many upsides to using copper pipe in residential applications, which is why it’s the most common material used by contractors and plumbers. We’ll list some of the pros below.
- Long average lifespan: Unlike some other materials, copper pipes last for around 75 years, on average. That minimizes repairs and how often you’ll have to access the pipes behind your walls.
- Low chance of contaminating drinking water: Copper can corrode over time, but there’s a relatively low risk of contamination compared to other metals and plastics.
- Lightweight: Copper is super lightweight, making it easy to transport and work with. It also often doesn’t require much bracing behind your walls.
Cons of Copper Pipe
Copper is the most common material used for plumbing pipes, but there are some downsides to consider:
- Expensive: Copper is one of the more expensive materials to work with, averaging around three to six times the price of PEX supply lines per linear foot.
- Not suitable for acidic or hard water: Acidic water — like the water you’d get from a well — is likely to speed up the corrosion of copper, which can leave metals in your water, so copper is only ideal if you’re connected to a public water system. Additionally, copper is especially prone to mineral buildup, which can cause issues with water pressure and supply over time.
- Hard to work with: DIY solutions with copper pipes are difficult. Copper is easy to cut, but making connections requires special tools and skills to “sweat” the lines. It takes some time and practice to learn how to do it properly.
The video below provides a quick look at how complicated connecting copper pipes can be:
SharkBite fittings are a common DIY solution for copper pipes, as they allow for quick connections without special tools or the need for sweating or soldering the pipes. These fittings are highly unreliable and will likely lead to severe leaks over time. We strongly recommend against using these fittings for any plumbing application.
2. PEX Pipe
Best for: PEX (cross-linked polyethylene) pipe is a somewhat recent innovation in plumbing that is best for supply lines for hot and cold water in homes.
Average cost: PEX piping averages around $1 per linear foot and ranges from $0.50 to $2, depending on the pipe diameter. The low cost makes it an appealing alternative to copper supply lines.
PEX pipe is flexible, making it easy to work with. The flexibility is thanks to the material it’s made of. PEX is a cross-linked polyethylene pipe material, also called high-density polyethylene (HDP) pipe material. It’s color-coded for ease of installation — blue for cold water applications and red for hot water applications.
The pipe comes in sizes ranging from ½ inch to 1 inch. Domestic water applications typically use ½-inch or ¾-inch PEX pipe.
Pros of PEX Pipe
PEX pipe is becoming more and more common for new construction and plumbing replacement or updating projects for a few reasons:
- Easy to work with: PEX pipe is soft and doesn’t require sweating like copper pipes, so cutting it and making connections are easier than copper, making it a better pipe material for DIYers to work with. Plus, it’s flexible, so you don’t have to deal with nearly as many connections.
- Affordable: PEX pipe averages around $0.50 per linear foot, which is around six times cheaper than copper. You also often need fewer connections and less piping overall, further reducing installation costs.
- Lower risk of freeze damage: PEX pipe is more flexible than copper, so it comes with a lower risk of bursting if the water inside freezes.
Cons of PEX Pipe
PEX pipe isn’t the be-all and end-all solution to expensive copper piping, as there are some downsides to consider:
- Sometimes not up to code: Many municipalities don’t allow PEX piping in their building codes, so it might not be an option for your home, depending on local regulations.
- More harmful to the environment: Plastic PEX pipe is not recyclable and more harmful to the environment than copper and other metals that can be recycled.
- More susceptible to pest damage: Squirrels and other rodents can chew through PEX, which could lead to plumbing leaks you might never see with more durable copper piping.
3. PVC Pipe
Best for: PVC (polyvinyl chloride) pipe is best for drain lines, while CPVC (chlorinated polyvinyl chloride) pipe can be used for cold water supply lines. In most cases, PVC pipe is used to carry greywater (domestic wastewater from showers and sinks) and blackwater (domestic wastewater from toilets) to your septic system or main sewer line. PVC pipe is also highly resistant to UV light and hot and cold temperatures, so it’s a common option for irrigation systems and pipes exposed to direct sunlight.
Average cost: The average cost sits at around $1 per linear foot for 1 ½-inch piping — the most common option for fixture drain lines.
PVC pipe is usually white and has thick walls. PVC is a hard plastic, so it’s relatively lightweight and semi-flexible. Unlike copper, connections for PVC pipe are easy to make using a two-part PVC glue. Most home supply stores like Home Depot carry long sections of PVC pipe and a wide range of connections for all applications, including P-traps, S-traps, T-joints, Y-joints, and more.
Pros of PVC Pipe
There are a few upsides to working with PVC pipe as a DIYer:
- Easy to work with: PVC connections are one of the simplest in plumbing. Most homeowners can easily handle PVC plumbing jobs without experience or special tools. Plus, it’s lightweight, easy to transport, and easy to cut.
- Affordable: PVC pipe averages around $1 per linear foot for residential plumbing applications, so it’s cheap to carry out repairs, even if you make mistakes.
- Corrosion resistant: PVC pipe is highly resistant to corrosion. If CPVC is used for cold water supply lines, you won’t get any chemicals in your water, even if your water is acidic (which well water typically is).
Cons of PVC Pipe
There are also a few drawbacks to working with PVC pipe for plumbing applications:
- Not suitable for hot water supply lines: PVC isn’t suitable for hot water supply lines, so it’s often skipped over altogether for supplying water, except for in-ground sprinkler systems.
- Not fire resistant: PVC isn’t heat resistant and won’t stand up to high temperatures, so the pipes will quickly melt if there’s a fire in your home. Unfortunately, melting PVC also releases toxic fumes into the air.
- Louder than metal pipes: Water running through plastic pipes behind your walls is often audible, which some homeowners don’t like.
4. ABS Pipe
Best for: ABS (acrylonitrile butadiene styrene) pipe is best for drain and vent lines in residential plumbing systems. It’s typically found under sinks and other fixtures and carries greywater or blackwater toward your main sewer line or septic system. Some electricians use ABS pipe as an insulative conduit for electrical lines, so be aware of that if you’re assessing an ABS pipe behind a wall.
Average cost: The average cost of ABS piping is around $0.80 per linear foot, but the total can range from $0.50 to about $5, depending on the thickness of the pipe wall and the diameter. Most domestic waste lines made of ABS pipe are 1 ½ inches in diameter.
ABS pipes are black and rigid, so they look like darker PVC pipes. They are semi-flexible, but connections are required to run piping through your home. Much like PVC pipes, ABS pipes are joined using a cement glue specifically made for ABS material, so working with this option is much easier than with copper piping. Long, straight runs and a variety of connections are usually in stock at home improvement stores.
Pros of ABS Pipe
There are a few upsides to working with ABS pipe for domestic drain lines and vent lines:
- Affordable: Affordability is the main draw to ABS over PVC for drain lines. On average, ABS is around half the price of PVC per linear foot.
- Easy to cut and connect: Like PVC, ABS is suitable for even inexperienced DIYers. Cutting can be done with regular saws, and connections are simple using a two-part cement glue that is highly durable and leak-free.
- Shock resistant and durable: ABS is more durable than PVC and can withstand higher impact and lower temperatures. Ultimately, that means it’s less prone to damage from freezing.
Cons of ABS Pipe
There are some drawbacks to ABS pipe that push some contractors and homeowners to stick with PVC or other drain line options.
- Sensitive to UV light: ABS will warp and crack if exposed to UV light, so it’s only suitable for indoor or underground applications, unlike PVC.
- Contains bisphenol A (BPA): ABS pipe contains BPA, a potentially harmful chemical that is added to ABS pipe to improve durability. Unfortunately, this makes it unsafe for use as supply lines, including cold water supply, so it’s not as versatile as PVC pipe.
- Louder than metal pipes: Since ABS is a plastic, you’ll likely hear water draining through it behind your walls. This can be off-putting for some homeowners.
5. Flexi Pipe
Best for: Flexi pipe, also commonly referred to as supply hose, is best for making short-range connections between speedy valves — often connected to copper pipes behind your walls — and fixtures, namely toilets and sink faucets. This piping is prohibitively expensive to use over long stretches, but the flexibility makes it ideal for connecting plumbing fixtures to roughed-in plumbing, especially for retrofits or for use in tight spaces where rigid water lines aren’t realistic.
Average cost: The average cost of a flexi pipe supply hose is around $10, but, depending on the length you need, you could pay anywhere from $5 up to $20.
A flexi pipe supply hose contains a flexible PVC hose which is usually enclosed within a braided steel protective layer. The connections on either end depend on the purpose of the line. In the picture above, the upper connection is made to connect to a toilet for water supply to the tank. The lower connection gets screwed onto your speedy valve. A line with two connections that look like the lower one in the picture would be for connecting a sink to a speedy valve.
Pros of Flexi Pipe
There are a few upsides to using flexi pipe as a short-distance domestic supply line:
- Easy to install: A flexi pipe makes it easy to connect plumbing fixtures to supply lines without having to deal with rigid plumbing. This allows flexibility in how close your fixture is to your speedy valve. It also requires no special tools to connect, so even inexperienced DIYers can easily install and replace them.
- Can handle high pressure: The PVC hose surrounded by braided metal is designed to withstand extreme pressure. It’s very rare to have one of these pipes burst, even if you have high water pressure in your area.
Cons of Flexi Pipe
There are just a few drawbacks to using flexi pipe for connecting your fixtures to your rigid plumbing lines.
- Expensive: On a per-linear-foot basis, this is one of the most expensive plumbing pipe options, so it’s not suitable for long runs of plumbing pipe. However, the convenience is worth the money for small applications like supplying water to fixtures.
- Won’t last as long as other pipes: While the connection for a flexi pipe is simple, it does mean that it won’t last as long as a sweated copper connection or a cement-glued PVC connection, so you’ll have to replace flexi pipes every five to ten years or so.
6. Galvanized Steel or Cast Iron Pipe
Best for: Galvanized steel or cast iron pipe is best for main waste lines. These pipes used to be used for supply lines as well, but copper has almost entirely replaced them for that purpose. Now, you’ll most commonly find these used for large waste lines that run to your sewer system, septic system, or cesspool, or as supply lines in older homes.
Average cost: Galvanized and cast iron pipe are quite expensive, ranging from $2 to $25 per linear foot, with an average of about $18. One reason for the high cost is the pipe size, typically 4 or 6 inches in diameter for main waste line applications.
Cast iron and galvanized steel pipes are usually the largest in your home, ranging from 4 inches up to 6 inches in diameter. They’re made of hard metal and typically black, but they could appear rust-colored if older. Generally, you’ll only find these running from toilets to your main waste line and used as the main waste line, which exits your home through your foundation and runs to either a public sewage system or a private waste disposal system.
Pros of Galvanized Steel or Cast Iron Pipe
Galvanized steel and cast iron pipes are common in home waste systems for a few reasons:
- Resistant to corrosion and rust: Galvanizing steel or cast iron helps these pipes resist deterioration. This contributes to a long lifespan, which limits expensive access and repairs.
- Resistant to crushing: These pipes have thick walls that withstand excessive force. This makes them a great option for underground waste pipes leaving your home.
- Highly durable: Steel and cast iron pipes have a lifespan of up to 100 years, somewhat justifying the high up-front price tag.
Cons of Galvanized Steel or Cast Iron Pipe
There are also some cons to using steel and cast iron, especially for certain plumbing applications:
- Expensive: These large metal pipes are expensive per linear foot, which is a drawback when running long lines for waste removal.
- Somewhat difficult to work with: Steel and iron pipes are heavy and bulky. Even though the connections can be made rather easily, maneuvering large sections of this piping can be challenging without extra help.
- Can leach metals into water: Steel and iron will both leach metal into your water, so these options aren’t suitable for plumbing supply lines.
7. Black Pipe
Best for: Black pipe is best for transporting natural gas into your home. It’s typical to see this type of pipe running to your gas stove, gas boiler, or other appliance that uses natural gas as a fuel source.
Average cost: Black pipe costs between $0.50 and $3 per linear foot, with an average of around $2.50. The most common size for residential applications is ½-inch-diameter black pipe.
Black pipe is, as you might guess, black. It’s completely rigid, as it’s made from black steel. It typically has threads on either end to connect to fittings or connections, all available in most home improvement stores. Even though this piping is used for natural gas, it’s considered a plumbing pipe and requires a plumber’s license to work with in most municipalities.
Pros of Black Pipe
Black steel pipe is common in residential gas applications for a few reasons:
- Fire resistant: Perhaps most importantly, black pipe is more fire resistant than other metal pipe options, including galvanized steel. This is crucial because it needs to maintain a seal on your natural gas supply in the event of a fire to prevent explosions.
- Not prone to leaks: Black steel is manufactured without a seam, which means it’s less prone to leaking than just about any other metal pipe option. This makes it ideal for transporting natural gas, which can be very dangerous if the supply lines are leaking.
- Durable: Black steel is about as durable as galvanized steel, so these lines can last for around 100 years without replacement.
Cons of Black Pipe
There are a few downsides to black pipe to consider before you move forward with any sort of DIY plumbing project:
- Only for professionals: Since black pipe is used to transport natural gas, it’s not advisable to work with it without a plumber’s license. Issues with natural gas can be extremely dangerous, which is why most municipalities mandate a plumber’s license to work with gas lines and a pressure test on any lines for transporting gas. You should consider hiring a plumber if you need a black pipe installation or replacement.
- Not ideal for transporting water: Steel pipe can leach metals into water, so it’s not ideal for use as a supply line. However, it can be used for domestic water distribution in areas where other options aren’t realistic or affordable, like some rural areas.
How To Correctly Measure Pipe Sizes
Regardless of the kind of plumbing pipe you’re working with, you should always make sure you measure the pipe carefully to ensure you get a proper fit. Most plumbing applications also do best with a specific pipe diameter, so pipe sizes are important even if you’re plumbing a new area in your home. We’ll detail the steps to measure your pipes below.
Step 1: Measure the Outside Diameter
First, you want to measure the pipe’s total diameter, including the pipe walls’ thickness. Ideally, you’ll use calipers for an accurate reading. Simply place the calipers over the pipe and take a measurement using the outside forks. Alternatively, you can use a tape measure. Just make sure you take a reading across the middle of the pipe to get the true diameter.
Step 2: Measure the Inside Diameter
Next, you’ll need to measure the inside diameter. You can do this using the inside forks of your caliper or a tape measure. If you use the latter, just be sure you measure across the center and only measure from inside wall to inside wall.
Step 3: Calculate the Material Thickness
Your last step will be to calculate the thickness of the pipe wall. You can subtract the inside diameter from the outside diameter and then divide by two to get the material thickness.
Step 4: Choose Your Pipe
Finally, you can use your measurements to choose your pipe. You can either measure the new pipe or just buy one that matches the outside diameter and material thickness.
So, How Do You Decide Which Type of Pipe You Need?
If you’re dealing with a plumbing issue in your home, you might be intimidated by the sheer number of pipe options available at your local home improvement store. Hopefully, the information we’ve provided above has helped guide you a bit toward the right choice for your project. We’ll also include some things to consider below to make sure you get the right kind of pipe for your situation.
- Specific application: Certain plumbing pipe options are best for specific applications, so this can be the easiest way to decide what kinds of pipe are even possible for your project. For example, if you’re running supply lines behind your walls for hot and cold water, you really only have two options: PEX and copper. Choose the type that matches your project based on our guidance above.
- Water quality: If you’re running water supply lines, you need to consider your water quality. Acidic water — usually from private wells — can corrode certain materials, including copper, so PEX might be a better option.
- Budget: If you have piping options based on your application and water quality needs, your budget might be an important thing to consider. For example, if PEX and copper are both options for your project, PEX will be about a sixth as expensive. Keep in mind long-term cost as well, as copper lines will last longer than PEX.
- Local building code: The building code in your municipality might dictate what kinds of pipe you can and cannot use. For example, PEX isn’t up to code in some areas, meaning copper or galvanized steel would be your only reasonable options for hot and cold water supply.
- Area of installation: If you’re installing pipes inside your home, most options will be just fine. If pipes will be subject to drastic temperature changes, UV (ultraviolet) light, or other environmental factors, then choosing the right pipe for your installation area can help narrow down your options.
- Experience or comfort with DIY plumbing: Finally, some pipe options are far more challenging to work with as a DIYer. For example, copper pipe is harder to cut and make connections with than PEX and PVC. If you plan on doing your project yourself, you might want to consider your experience when deciding on the type of pipe that’s best.
Ultimately, the type of pipe you use for your plumbing repair or replacement project should be driven by the application. Depending on where you live and the use case for the pipe, you might have a few different options. You can use the information above as a guide to help you choose the right kind of plumbing pipe or assess which pipes you’re looking at in your home if you’re unsure.
Below, we’ll answer some of the most common questions we get about the different types of home plumbing pipes.
FAQs About the Types of Plumbing Pipes
What is the most durable plumbing pipe option?
The answer to this question depends on the application. Overall, galvanized steel and cast iron pipes have the longest lifespan, averaging around 100 years. However, these options aren’t ideal for water supply lines due to cost and potential leaching, so copper lines that last around 40 years are considered the most durable for hot and cold water supply lines.
Is PEX pipe better than PVC?
PEX is superior to PVC in some cases. Specifically, it’s a flexible pipe that’s also super lightweight, making it easier to work with than PVC. The connections can also be made without glue, so ease of use is better with PEX. PEX can also safely carry hot and cold domestic water, while PVC will leach chemicals into hot water and can warp and crack over time if exposed to severe heat.
With that being said, PVC has a longer lifespan — up to around 70 years as opposed to 40 for PEX — and PVC is more affordable per linear foot.
Ultimately, neither is exclusively better, but specific plumbing applications may call for one over the other.
What are the disadvantages to copper plumbing pipes?
Copper plumbing pipes can corrode over time and slowly leach metals into your drinking water, especially if you have well water, which tends to be acidic. Copper is also one of the most expensive pipe options per linear foot. Most importantly for DIYers, cutting and connecting copper pipe can be challenging, and it requires special tools and skills that many homeowners don’t possess.
What is the most common type of plumbing pipe?
The most common type of pipe for plumbing depends on the application. As far as water supply lines go, copper pipe has long been the preferred option. For small drain lines, PVC and ABS are both popular, with PVC appearing more often in homes. For main sewer lines, galvanized steel or cast iron pipes are the most common. Black pipe is the only type you’ll typically see for transporting natural gas.