PEX and Plumbing for Homeowners

For most homeowners, plumbing means turning on faucets (dishes, the shower), appliances (dishwasher, washing machine) or flushing the toilet. We only think about plumbing when there's a leak and few homeowners understand how we get hot and cold water when we want it. Fortunately building codes establish design guidelines that insure our home's plumbing system is properly designed and safe for our families.

Water pipes initially were made of wood until cities began to use cast iron for water mains. We still expect our home's plumbing to be made of copper and that's where PEX or cross-linked polyethylene (PEX) enters our story. PEX was adopted first in Europe but with escalating copper prices, it's now gaining popularity in the US according to the NY Times article, If Copper Pipes are Too Costly …

Quick Facts About PEX

PEX is growing in popularity as an alternative to copper piping in plumbing systems for residential homes. You will recognize PEX piping by it's color – red for hot water and blue for cold water. It comes in various sizes (1/2″ and 3/4″ are the most common), different lengths and there are 3 different types of PEX based on their respective manufacturing processes.

• PEX has been used in Europe since the mid 1970s. In North America, it was first used for radiant floor heating in the mid 1980s. PEX is now approved for potable hot and cold water supply systems as well as hydronic heating systems across the US and Canada.
• PEX is easier to install than rigid pipes and doesn't require soldering to join pipes together. It's flexible and available in long lengths which means fewer connections are required to deliver water to plumbing fixtures.
• PEX plumbing systems cost less to install and they deliver water to fixtures faster, making PEX systems more energy efficient.
• Based on testing and usage over 30 years, PEX has proved to be very durable without some of the problems often found with copper piping. A key advantage is that PEX piping typically expands if the system freezes and returns to its original size when the water thaws.

Learning More About PEX

While I've watched plumbers install PEX, I've never used the PEX crimping tools. From my experience running a handyman business, I understand how important the design of your plumbing systems is and how quality materials and installation minimize maintenance headaches.

If you want to learn more about PEX for your home, you should talk to your plumber. If you're curious and want to learn more about the technology, and gain insight into how those involved in construction adopt new materials like PEX, you will enjoy reading Design Guide: Residential PEX Water Supply Plumbing Systems:

1. Introduction: Background to educate the user about the history and uses of PEX piping.
2. Advantages: Various advantages to using PEX piping in residential buildings.
3. Material Properties: Unique properties of PEX piping.
4. Joining Methods: Explanations of the various types of fittings and their joining methods.
5. Types of PEX Plumbing Systems: Descriptions of the3 types of PEX piping system designs.
6. Code Acceptance: Information on major plumbing codes and relevant jurisdictional code provisions for PEX piping.
7. Design: Designs and performance details of the three basic plumbing layouts for four common house configurations to assist in evaluating which system provides the best balance of performance, ease of installation, and cost for a particular house.
8. Lab Testing & Performance: System performance comparison of three plumbing systems.
9. Installation: Detailed instructions for installing PEX piping.
10. Testimonials: Quotes from plumbers and home builders on their experiences with PEX piping.
11. Other Applications: Other uses of PEX piping.
12. Additional lab testing data.
13. New Installation Checklist to aid plumbers with the process of installing PEX piping.
14. Resources for additional information beyond this Design Guide.