Why galvanized pipe wears out
Galvanized pipe is steel coated with zinc. Over decades the coating wears away and the steel underneath rusts. Rust and mineral scale build up on the inside wall, so the opening gets smaller and the water that comes through can pick up color.
Because the damage is inside, galvanized pipe can look solid in the garage while the flow at the far bathroom has dropped to a trickle. Threaded joints are also common weak points, since the threads cut away part of the pipe wall.
How to tell if you have it
- Exposed pipe that is dull grey and attaches with threaded fittings.
- A magnet sticks to it firmly; it does not stick to copper or plastic.
- Scratching the surface shows silver-grey metal, not copper color.
- Brown or yellow water when taps are first opened.
- Pressure that has fallen gradually across the house.
Partial fixes versus replacement
Replacing sections
- Can restore flow to one problem area.
- Leaves other galvanized runs in place to keep corroding.
- Creates joints where new and old materials meet, which need the right fittings.
Replacing all supply lines
- Removes galvanized from the whole system at once.
- Usually restores even pressure at every fixture.
- Requires wall access, a permit and planning.
What replacement typically involves
Survey
A plumber identifies which lines are galvanized, from the main shutoff to each fixture.
Plan the new route
New copper or PEX lines are planned through the attic, walls or crawl space, depending on the house.
Install and connect
New lines are run and connected fixture by fixture, often while the old system still serves the house.
Test and inspect
The new system is pressure tested and, where a permit applies, inspected by the city before walls close.
Questions to ask
- Is the line from the meter to the house galvanized too, and is it included?
- How will you join new pipe to any remaining old pipe?
- Will the old galvanized be removed or abandoned in place?
- What should I expect for water quality right after the switch?
Common questions
Can rusty water from galvanized pipe be flushed out?
Flushing may clear loose sediment briefly, but it does not reverse corrosion inside the pipe. Ask a plumber about the condition of the lines.
Is the street-side pipe my responsibility?
Responsibility usually splits at the meter. Ask your water provider, named on your bill, where their side ends.
Do I need to replace galvanized drain pipe too?
Drains are a separate system. Some older homes have galvanized drain lines; ask for a separate assessment if you have slow drains.
General information for Yorba Linda, not a quote or professional advice. In an emergency, call 911.