Galvanized steel
Common before the 1960s, galvanized steel rusts from the inside. Pressure drops, water turns brown, and leaks start at threaded joints.
Polybutylene
Grey plastic pipe used between the late 1970s and the 1990s. It can become brittle and fail without warning, especially at fittings.
How to recognise them
- Galvanized: grey metal, threaded joints, fridge magnet clings
- Polybutylene: grey or sometimes blue flexible plastic, often stamped PB
What to do
- Identify all the pipe you can see.
- Ask your insurer about coverage.
- Plan replacement before a failure.
Replacing them, step by step
We usually start where the line enters the house, replacing the main shut-off and the first run of pipe, then work out to each fixture. Galvanized lines are cut and removed where accessible, or abandoned in walls. Polybutylene comes out with its fittings. New lines are PEX or copper, with a new stop at every fixture.
Opening a ceiling to reach old pipe is also the moment to look for wiring or venting issues; we flag anything outside our trade for the right professional.
Related
See repiping, water service line replacement and buying a home.
Keep-handy checklist
- Hang a flanged plunger and a pail beside the basement floor drain
- Shine a light under each vanity and kitchen sink every spring and fall
- Pencil the install date on the water heater and the sump pump
- Pull the pop-up stopper and clear the hair every couple of months
Your questions, answered plainly
Is PEX the same as polybutylene?
No. PEX is a different material and is widely used today.