Installer Water Line Testing

It seems like water supply piping in manufactured housing is constantly changing. From polybutylene in the old days, to CPVC, and now PEX. One thing that has also changed is the requirement for water supply line pressure testing as a part of installation.

If you are like me, you question the need to test water piping in the field (especially in single section homes). Didn’t the manufacturer test the piping before the home left the factory?

Regardless of what either of us think, it is now required. My concern would be a small leak (possibly a pin nail or screw) would go undetected until it filled the bottom board with water (see below) and eventually cause significant damage to the home. The installer could find himself in court or a some other dispute resolution proceeding.  bb-water-leak1I would imagine one of the first questions to be asked would be if the installer tested the water lines as is required in the manufacturers installation manual.

“…check the water system for leaks using one of the procedures described below. Before testing, close all water faucets, spigots, and toilet tank float valves…”

The instructions go on to tell you to conduct either a hydro-static (with water) test which is identified as preferred, or the pneumatic (air) test. Ok…you can read the installation instructions for the details (see below for an excerpt from one manufacturers manual). Both of these tests call for the installer to pressurize the system to 100 psi for 15 minutes.

But there are two more important notes tucked away along the margin of the installation manuals:

  • Do not pneumatically test CPVC systems.
  • Pneumatically test Flow Guard Gold systems only at low pressure levels (20 psi or less).

This seems confusing to me, but here is my take.  If the home has CPVC water supply lines, you should conduct a hydro-static test. If you must conduct an pneumatic test, and the CPVC water supply piping is identified as Flow Guard Gold, do so only at very low air pressure.


I won’t even venture a guess as to what the issues are here.flow-guardI strongly suggest that installers need to be aware and react accordingly. Talk to the manufacturers you work with to see if they use Flow Guard Gold.

As the professional installer, make sure you are up to speed on these issues. Do you have the appropriate testing apparatus to conduct the test? As proof of a properly conducted test, how about snapping a date stamped picture of the pressure gauge of every home you install?


Speaking of installer records, make sure you document the test on the Complete Installation Checklist.


Should you discover a leak, you need to report it to the retailer and/or the manufacturer. And depending on what caused the leak, maybe you should be billing someone for the cost of repair. If you do repair a CPVC leak in the field, make sure you allow the solvent (glue) sufficient time to dry before retesting the plumbing system (generally 30 minutes minimum). If you need to repair PEX or polybutylene, make sure your tools are properly calibrated.


Truth be told, I don’t see too many water pressure tests being conducted in the field. I hope you are the exception, and if not, the time to start is now.


One thought on “Installer Water Line Testing

  1. We have seen this more than we would like. The manufacturers do a great job, but sometimes the crimp ring on the shower diverter does not get crimped and still works without leaking, for a little while. We look for a leak there during the hydrostatic test. Sometimes the leak will develope a couple weeks later. We are starting to pull the access during the test to check anyway.


Leave a Reply to Neil Bandel Cancel reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s