Main Water Supply Inspection

There are 6 different types of main water supplys and water lines used today:  copper, galvanized steel, lead, pex, cpvc, and polly.

Galvanized Steel Supply CPVC Water Supply pex water supply
Galvanized Steel Water Supply CPVC Water Supply

Pex water supply

Copper supply Lead water supply

Black Poly

Copper Water Line

Lead Water Supply Black Polly Water Supply


Copper: The most commonly used main water supply line found today.

Lead: The easiest way to distinguish a lead water supply line is a distinctive “bubble” in the line, typically next to the meter.

Galvanized Steel:  Found in most older homes, galvanized steel was used as a main water supply and was also used for the main water lines (leading to all the faucets in the home).

Black Polly:  Commonly used today as a main water supply for homes with a well.

CPVC:  The most unlikely water line used today.  It is primarily used by homeowners that are installing their own water lines (leading to faucets).

Pex:  A plastic like material that is becoming more commonly used today for the main water lines (leading to all the faucets in the home) because of the high cost of copper, and due to the fact that it is easier to install.


It is very important to always look for the following when inspecting water lines:

  1. Water leaks in all the joints.
  2. Water leaks in all the shut off valves.
  3. When Galvanized and copper pipes are connected together they should have a Dielectric union Pipe fitting installed.   A dielectric union pipe fitting is designed to hold together two different types of metal.

Galvanized lines that run horizontally through the house have the tendency to build up rust and create water flow blockages.  Run at least 2 faucets at the same time and check the water pressure to determine that the pressure is adequate.  Two dissimilar types of metals that are connected together (such as copper and galvanized steel) should always have a dialectic union installed to prevent corrosion.


Proper connection between copper and galvanized steel dilectric union
Rust build-up in galvanized pipes Proper connection between copperand galvanized steel Dielectric union