The Differences Between CPVC, Copper Pipe, and PEX Pipe

When it comes to installing new pipes or making repairs, plumbers have their preferred options. These options include PVC, CPVC, copper, and PEX tubing. Having some knowledge about each type of pipe will help you understand the distinctions between CPVC and PEX pipe as well as copper pipe. The debate between CPVC, copper, and PEX is a heated one, with factors such as price and ease of installation taken into consideration. Let’s delve into all of these aspects below.

Table of Contents

• Common Application: Replacing Galvanized Pipe
• Comparing Labor Costs
• CPVC for Pipes
  • Advantages of using CPVC
  • Considerations when using CPVC piping
• Copper Pipe: The High-End Mainstay
  • Advantages of using copper pipe
  • Disadvantages of using copper pipes
• PEX Tubing (Cross-Linked Polyethylene)
  • Why use PEX tubing?
  • PEX overview
• CPVC vs Copper vs PEX Material Comparison
• So, Who Comes Out on Top in the CPVC vs Copper vs PEX Tubing Race?

Common Application: Replacing Galvanized Pipe

Many older homes still have galvanized pipes, which were commonly used in the past for bringing potable water into houses. However, galvanized pipes have several disadvantages. Over time, they are prone to internal corrosion, which can significantly restrict water flow after around 30-40 years. As a result, homeowners often replace galvanized piping when renovating areas like bathrooms and kitchens to utilize the original plumbing from older homes.

Comparing Labor Costs

Copper has been the dominant material for piping, used in about 80% of new homes built in the past three decades. However, CPVC is steadily gaining popularity among remodelers and DIY enthusiasts due to its ease of use. Unlike copper, CPVC piping does not require soldering. Each of these products has its own advantages and disadvantages. The choice between CPVC and PEX depends on your familiarity with the material, as well as the design and function requirements of your piping system. Both CPVC and copper pipes can be used without any major issues. It is crucial to have someone experienced in best practices of each material to ensure proper installation. To help you decide which material works best for you, we will look at the pros and cons of each.

CPVC for Pipes

CPVC piping has been in use for over 40 years and is popular among amateur remodelers and DIY enthusiasts. CPVC can withstand temperatures of up to 140 degrees and is as safe to use as copper pipe. It has high elasticity and can handle high amounts of heat. CPVC pipes have a different outer diameter than copper or PVC pipes, so this should be considered when connecting to older pipes, such as galvanized or copper pipes. Compared to copper, CPVC is lightweight and easy to install. It is also more cost-effective, especially as metal prices have steadily increased in recent years.

Advantages of using CPVC

• Corrosion and wear resistance
• Smooth holes improve flow and reduce water noise
• High impact strength
• Simple and cost-effective installation
• Competitive price compared to copper, making it less prone to theft on the job site
• Lightweight
• Self-insulating to minimize heat loss
• Flame retardant with low smoke density
• Pressure rated to withstand high temperatures
• Flexibility eliminates water hammer
• Inert to acidic soils and corrosive water sources
• Can be directly buried under the floor without reacting with concrete
• Non-conductive
• Eliminates pressure leaks at solder joints
• Minimal sweating or condensation

Considerations when using CPVC piping

• Prone to cracking during earthquakes
• Typically requires a cure period of 24 hours or more in cold weather before pressurizing with water

It is important to note that CPVC has been approved for potable water delivery by all national building codes in the United States and Canada. Manufacturing standards have been established to ensure consistency and safety (ANSI/NSF-61 standard).

Copper Pipe: The High-End Mainstay

Copper pipe is widely used in the United States and has been around since the late 1920s. In 1932, the American Society for Testing and Materials (ASTM) created Standard B88 to establish seamless copper piping as the industry standard. By the early 1980s, copper water pipe production, sales, and installations surpassed 5 billion linear feet per year. Copper pipe is an excellent solution for residential and commercial plumbing, especially when the pH of the water supply is close to neutral.

One of the main concerns with using copper tubing is the issue of pinhole leaks. Older homes with horizontal cold water supply lines often experience pinhole leaks caused by corrosion, resulting in uneven breakage of pipe walls and leakage. Potential causes of pinhole leaks include the use of water softeners, high pH, and excessive flow rates, among others.

Advantages of using copper pipe

• Proven long-term durability (15-20 years) in non-acidic installations
• Biostatic properties, preventing bacterial growth
• Anti-seismic
• Fireproof with a high melting point
• Complies with all building codes
• Contemporary copper tubing is 99.9% pure according to ASTM specifications
• High rated internal working pressure
• Fast cure time, allowing for pressure testing in as little as 10 minutes
• Can be bent to avoid obstacles, minimizing the need for joints
• Available in annealed (soft) and stretched (hard) versions
• Smaller outer diameter compared to CPVC
• Joints are not bulky

Disadvantages of using copper pipes

• Some reports of a metallic taste in the water
• Erratic prices due to market forces
• Can develop pinhole leaks with acidic water
• Restricted to pH levels below 6.5-6.8 in certain areas
• Risk of lead or copper leaching into water supply
• Labor-intensive installation requiring skilled plumbers
• Calcium buildup may restrict water flow
• High initial installation costs
• Prone to heat loss and requires insulation
• Condensation may occur if not properly insulated
• Can be noisy at high water speeds
• Susceptible to water hammer at high speeds, requiring water hammer arrestors
• Joints can fail at high temperatures
• Fire hazard during installation with gas torches
• Repairs are challenging and require special training and tools

Although the health effects of copper plumbing are relatively unknown, the EPA lists copper as a contaminant in drinking water. The highest allowable level is 1.3 mg/L. New copper fixtures often release more copper initially, and corrosive or acidic water can exacerbate the issue. Older copper fixtures may also contain higher levels of lead, particularly those with lead solder used before 1987.

PEX Tubing (Cross-Linked Polyethylene)

PEX stands for cross-linked polyethylene, a type of plastic tube produced using a specific manufacturing process. Crosslinking creates connections between the polymer chains of the plastic. PEX tubing is manufactured using three different methods (PEX A, B, and C) that represent different approaches rather than varying grades of PEX. The extrusion process involves heating the material under pressure and pulling it through a die.

PEX pipe has been around since the 1960s, but it only gained popularity in US plumbing applications in the 1980s. Installers prefer PEX due to its flexibility (1/2″ tubing can be bent in an 8″ radius) and the ability to run it from the supply to the destination in one go, saving significant installation time compared to copper or even CPVC.

Why use PEX tubing?

• Can handle a wide temperature range, making it suitable for hot and cold water supply lines and even radiant floor heating systems
• Can be installed under or penetrate slabs with ease
• Operates in a “home run” configuration, allowing independent shut-off for repairs without interrupting water flow

PEX is available in various diameters and is typically packaged in coils or straight tubing. Mechanical or compression fittings are used for installation, which requires some special tools not commonly found in a casual homeowner or remodeler’s toolkit.

PEX overview

• Requires brass fittings for installation
• Installation necessitates special tools
• Extremely durable and expandable when properly installed

There are three types of PEX on the market: PEX A, B, and C. PEX C is less common in whole-home applications, so we will compare A and B in layman’s terms. By doing so, we can uncover some key differences.

CPVC vs Copper vs PEX Materials Comparison

To present a clear picture in the CPVC vs copper vs PEX debate, let’s assume a simple configuration consisting of two 100 ft lengths of 1/2″ pipe, each connected from source to faucet and passing through a 90-degree elbow. We won’t include any fittings or adapters at each end, only those required for the end-to-end connection. Some specialized tools not commonly found in a standard toolkit will also be considered. Refer to the table below for a detailed comparison.

NOTE: Using PEX tubing in a home run configuration may incur additional costs of $100-250 for a multi-port manifold that splits incoming hot and cold water and distributes it throughout the home.

So, Who Comes Out on Top in the CPVC vs Copper vs PEX Tubing Race?

In summary, CPVC emerges as the clear winner in terms of cost and ease of installation. PEX tubing is significantly less expensive and becomes even more cost-effective when tooling expenses are eliminated. Copper remains the most expensive option. However, professionals and homeowners still consider it the premier high-end solution for unknown reasons. If we were to construct new buildings, we would opt for PEX in our own homes. In older houses, we tend to replace copper (where possible) with CPVC, using copper only when it saves time and effort during repairs or renovations.

There is no definitive right or wrong answer in the CPVC, copper, and PEX debate. Understanding the methods and materials is crucial for tradespeople, as it can save them money and time during pipeline installations, leading to more job opportunities. As consumers, we often have limited choices. Nevertheless, this guide should provide you with an understanding of the variables involved in making the right choice for your specific needs.