Is PEX the right pipe material for your project?

Copper, galvanized steel, PVC, CPVC, PEX… it can be tricky to decide which pipe material to choose when you’re replacing leaky old pipes or installing a new potable water system. Get to know the ins and outs of PEX pipe to help you decide if it’s the right product for your DIY plumbing project. [Photo credit: istock.com/sndrk]

With a little knowledge and the right tools, you can tackle that faulty pipe or update your home’s water system with confidence.

PEX (crosslinked polyethylene) has been used in Europe since about 1970 and became popular in North America in the 1980s. PEX plumbing is favoured largely due to its flexibility, durability and heat-resistance. PEX can be used in temperatures ranging up to 82.2°C (180°F) in plumbing applications and up to 93.3°C (200°F) in heating applications.

Common household uses include:

• Hot and cold potable water applications.
• Water service lines.
• Radiant heating and cooling systems.
• Snow melting applications.
• Residential fire-sprinkler systems.

Always make sure the PEX pipe you select is suitable for the type of application. For example, not all PEX tubing is approved for use with potable water.

PEX is approved for all model plumbing codes, however, some jurisdictions may have additional requirements, so always check local building code regulations.

As with all plumbing materials, there are advantages and disadvantages to working with PEX.

Advantages:

• Durable and resists freeze-breakage, corrosion, pitting and scaling.
• Flexible and easy to use. PEX tubing can be gently curved around corners, reducing the number of connections for a quicker, easier installation.
• Quiet. It delivers water flow without the “water hammer” noise common with copper pipes.
•  Leak resistant. Due to its flexibility, it uses fewer fittings so there’s less of a chance leaks will occur at joint connections.
• Energy efficient. PEX pipes reduce heat transfer, conserving energy and reducing costs.
• Versatile. Piping is available in a range of lengths and sizes.
• Low cost. PEX pipe is less expensive than copper pipe. It’s also quick to install, low-maintenance and energy-efficient, making it less costly over time.
• Sold in colour-coded rolls so you can easily differentiate between hot and cold water lines.

 
Disadvantages:

• PEX pipe can’t be used outdoors as it degrades under UV light.
• Must not come in contact with direct flame; it releases toxic smoke in a fire.
• Shouldn’t be installed in contaminated soils as it can be permeated by outside contaminants.
• It’s not recyclable.
• PEX can be damaged if exposed to high chlorine concentrations.

When choosing between PEX, copper and CPVC for your home plumbing projects, consider the following:

• PEX and CPVC (chlorinated polyvinyl chloride) are similar in cost; copper is more expensive.
• PEX is safe to use; it doesn’t require soldering, glue or solvents.
• PEX resists scale build-up common to copper pipes.
• PEX resists freeze-breakage better than CPVC or copper.
• PEX fittings (particularly compression ones) are usually more expensive.
• Since PEX is more flexible and is available in long lengths, it’s better for “fishing” through walls in remodelling.

Good to know!

While many existing homes have copper piping, PEX is now the dominant technology for residential water distribution and radiant heating systems, and usage continues to grow. PEX is now common in both renovations and new construction.

Consider the following details when choosing PEX pipe:
Sizing

• PEX is available in short lengths for smaller projects as well as in long rolls. It comes in coils up to 305 m (1,000 ft.) and straight lengths up to 6 m (20 ft.).
• It ranges in diameter size from 6.4 mm (1/4 in.) to 101.6 mm (4 in.); 12.7 mm (1/2 in.), 19.05 mm (3/4 in.) and 25.4 mm (1 in.) are the most commonly used sizes. 
• Sizing is usually classified by outside diameter (OD), commonly called copper tube size (CTS).

Good to know!
PEX must be labelled with all relevant information including: manufacturer’s name, standards and codes, sizing, ratings and fitting designations.

Fittings and tools

• PEX fittings are usually made of brass, but also come in copper, stainless steel and plastic.
• PEX is joined in many different ways including push-fit fittings, compression fittings and specialty PEX tools with crimp rings.
• Three basic tools commonly used with PEX tubing are a crimping tool, a pipe cutter and a de-crimping tool.

 
Important!

Always purchase the PEX fittings and PEX tools recommended by the manufacturer of the PEX pipe you select. While differences between the fittings and pipes may seem minor, using the wrong tool to create a joint may cause leaks.

When you set out to purchase PEX pipe, consider the following:

• What type of application do you need it for?
• Does it meet the required industry standards for this type of application?
• Do you know the length, size and diameter(s) of the pipe you need?
• Do you have the correct PEX tools and fittings?

Now that you have a better understanding of the benefits of PEX pipe, you can decide if it’s the best material for your household plumbing project. With a little knowledge and the right tools, you can tackle that faulty pipe or update your home’s water system with confidence.