Zinc-coated steel water pipe, standard in homes built roughly before 1960. Its serviceable life is on the order of 40 to 60 years (averaging around 50), and once the protective zinc wears through, the steel underneath corrodes and scales up from the inside, narrowing the bore like a clogged artery.
$6,000 to $15,000 to repipe (partial fixes possible)Address soonPlumbing
The quick answer
Galvanized steel supply pipe (standard before ~1960) corrodes and scales up from the inside, so it's usually near end of life, you'll see weak upstairs pressure and rusty water after the house sits. A magnet sticks to it, which tells it apart from lead. A repipe runs about $6,000 to $15,000. Run several taps during your visit and have a plumber confirm how much life is left.
You are reading the galvanized steel supply piping page. Type the year the house was built and I will tell you what else tends to be true at that age, what it costs, and what to ask. One number, ten seconds.
Free. No account. Educational and impartial, not a home inspection.
Why it matters
In most homes that still have it, galvanized supply pipe is near or past end of life. The tells are low water pressure (worst upstairs or when two fixtures run at once), rusty or discoloured water after the house has sat, and a rising risk of pinhole leaks. Corrosion can also trap small amounts of lead at the scale where galvanized pipe once connected to a lead service line. It's less of an insurance flag than poly-B or lead, but it's a real, easy-to-verify cost worth pricing into an offer.
How to spot it
Dull grey threaded steel pipe (screwed joints, not soldered like copper); it's magnetic, a fridge magnet sticks, which is the quick way to tell it from lead (lead is non-magnetic); rust staining at the threads; and weak flow when you open several taps at once.
What it costs
Same scope as a poly-B repipe: the GTA market runs roughly $6,000 to $15,000 (larger or finished homes to $18,000). Partial fixes are possible but the corroding pipe that remains keeps corroding.
What to do
Address soon. Have a licensed plumber confirm the material and how much remains, run the taps during your walkthrough to feel the pressure, and budget for a repipe.
Education and triage, not a home inspection. Casaroo flags galvanized pipe and weak flow from your photos and notes, a licensed plumber confirms how much life is left.
Common questions
Will insurance cover a house with galvanized pipes?
Galvanized is generally less of an insurance flag than poly-B or Kitec, but old supply piping raises water-damage questions, and insurers price water damage carefully. It is still worth one call to your broker on the specific address rather than an assumption.
Can I replace just the worst section?
You can, and partial repipes are common. The catch is that the galvanized pipe you leave in place is the same age and keeps corroding, so a plumber should tell you whether a partial fix buys years or months. A full repipe runs $6,000 to $15,000.
How do I tell galvanized from lead?
A fridge magnet. Galvanized steel is magnetic and the magnet sticks; lead is not magnetic and it does not. Galvanized also has threaded, screwed joints rather than the soldered joints of copper. This is a thirty-second check most buyers never do.
Does galvanized piping mean the water is unsafe?
Not by itself, but corrosion scale can trap small amounts of lead where galvanized pipe once connected to a lead service line. If the home is old enough for that combination, a water test answers it and a plumber confirms the service line material.
Lifespan figures are industry estimates and vary with water chemistry; a licensed plumber confirms condition. Casaroo flags, it does not inspect.
Last reviewed 2026-07-10.
This guide is general education, not a home inspection and not advice for your specific property. Always
consult the appropriate licensed professional, and get a licensed home inspection before you remove conditions
or buy. Cost ranges are 2026 estimates that vary by region, size, and access; confirm specifics with a
qualified professional.