Galvanized Steel Plumbing

What Is Galvanized Steel Plumbing?

Galvanized steel pipe is steel piping coated in zinc to resist corrosion, and it was the standard water supply material in North American homes from the early 1900s through roughly the 1960s, with some use continuing into the 1970s. It predates both copper and the plastic piping systems (like Poly-B, Kitec, and PEX) that followed it.

Why It's a Concern

The zinc coating that protects galvanized pipe from corrosion wears away over decades. Once it's gone, the underlying steel begins to rust from the inside out. Because this corrosion happens internally, a pipe can look fine from the outside while being significantly narrowed or compromised inside — reducing water flow, causing discoloration, and eventually leading to leaks or bursts.

How to Identify It

Galvanized pipe is dull grey, threaded at joints, and magnetic — a simple magnet test can help distinguish it from copper or plastic piping. It's most commonly visible in a basement, crawlspace, or utility area. Homes built before 1960, or homes from the 1960s and early 1970s that haven't had plumbing updates, are the most likely candidates.

Signs of a Deteriorating System

• Rust-coloured or discoloured water, particularly after taps sit unused
• Noticeably reduced water pressure, especially if some fixtures are worse than others
• Visible rust or corrosion at pipe joints and threaded fittings
• Banging, whistling, or groaning noises suggesting internal blockages

What We Look For

We check visible piping material throughout the home, note the presence of galvanized supply lines where accessible, and flag water pressure and discoloration issues that may point to internal corrosion — even in sections of pipe we can't see directly.