How Corrosion Wears Down Older Plumbing (and How to Prevent It)

Decades of hard water, oxygen and heat corrode pipes, fittings and water heaters from the inside, and a system installed in the mid-century building boom may now be well past the age when things start to fail.

Why corrosion is so hard on plumbing

Galvanized steel rusts from the inside out, while its zinc coating slowly wears away. Copper can develop pinhole leaks when water chemistry or flow wears the wall thin, and mixed metals can corrode each other at joints. Hard water also leaves mineral scale that narrows pipes and coats tank bottoms.

Materials that hold up well

PEX tubing

Flexible, resistant to corrosion and scale, and now a common choice for repipes.

CPVC

Good chemical resistance and a practical option for many whole-house repipes.

Quality fittings and valves

Where metal is needed, such as at water heater connections and shutoff valves, use good brass or stainless parts with compatible fittings.

Maintenance habits that add years of life

• Schedule an annual plumbing inspection.
• Flush the water heater each year and check the anode rod, replacing it when it is mostly consumed.
• Watch for green or white crust on fittings, a sign that corrosion or scale has started.