The Plastics Pipe Institute Inc. (PPI) recently published its new PEX Plumbing Distribution Systems Design and Installation Guide, the third edition of a key industry handbook first published 20 years ago.
It provides information and resources necessary to design and install PEX hot- and cold-water plumbing distribution systems in residential, multi-family, and commercial buildings. A joint industry publication from PPI, the Plastic Pipe and Fittings Association (PPFA) plus Home Innovation Research Labs (HIRL) with support and input from IAPMO and ICC, it is available on PPI’s Building & Construction Division website as a free download. Printed copies will be available for sale during the second half of 2026.
This 156-page third edition includes updates to reflect the advancements in PEX materials such as tubing, manifolds, and fittings; updates to code acceptance for PEX plumbing systems; new design recommendations; and revisions to installation techniques. New information has been added to every chapter of this guide, which also includes a new chapter about water service line applications with specific installation instructions.
“Since the second edition of this guide was published more than 10 years ago, many aspects of PEX plumbing systems have evolved,” says Lance MacNevin, senior director of engineering for PPI's Building & Construction Division. “In addition to being the most common hot- and cold-water distribution material in residential plumbing, PEX tubing is now widely being used in commercial plumbing applications due to its flexibility, resilience, proven performance, and potential time savings during installation. With so much new information to share, as well as the knowledge learned from over 30 years of North American plumbing applications, PPI members felt it was time to do a total re-write of this guide, while also including many more pictures and graphics to make it easier to follow.”
According to PPI, crosslinking technology for polyethylene was pioneered in Europe in the late 1960s, with the first PEX radiant heating systems installed in 1972. Since then, PEX has had a 50-year history of successful use around the world for a variety of demanding applications. In the U.S., it was first adopted into the BOCA National Plumbing Code in 1993 (BOCA became part of ICC).
Adds MacNevin, “PPI is grateful to our members who provided pictures, graphics, technical content, and many hours of collaboration to finalize the third edition. We also recognize significant contributions from PPFA and HIRL in making this guide a reality."
