Galvanized steel supply lines — standard in homes built before the mid-1970s — have a lifespan of 40-70 years. If you are in a 1960s home in Scotch Plains, Westfield, or Cranford, the math is working against you. Here are the signs to watch for.
1. Discolored water from the cold tap
Brown or rust-colored cold water is the clearest indicator of interior pipe corrosion. Hot water discoloration can come from the water heater; cold water discoloration comes from the supply lines. Run your cold tap for 2 minutes — if it clears, corrosion is moderate. If it stays rusty, the pipes are far gone.
2. Low water pressure throughout the house
Galvanized pipe corrodes from the inside out. Scale and rust buildup narrows the pipe interior progressively. A 3/4-inch supply line can be reduced to the flow of a 3/8-inch line without any visible exterior damage. If pressure has declined noticeably over several years, internal buildup is the likely cause.
3. Recurring pin-hole leaks
One pin-hole leak in galvanized pipe is a warning. Two or three in a short period means the pipe wall integrity is failing across the run. Patching individual leaks is not a long-term solution — the next failure will appear nearby.
4. Polybutylene pipes (gray plastic)
Homes built between 1978 and 1995 may have polybutylene (PB) supply lines — gray plastic pipe that was recalled due to widespread failure. If your home has these, repiping is not a question of if but when. Check under sinks and near the water meter for gray plastic pipe with metal or plastic crimp fittings.
5. Visible exterior corrosion at connections
Blue-green staining at copper connections indicates electrolytic corrosion. Orange-brown staining at galvanized fittings indicates active rusting. If you can see corrosion on the accessible portions of pipe under sinks or in the basement, the hidden runs are in the same or worse condition.
A whole-house repipe typically runs $4,000-$9,000 depending on home size and access. Done proactively, it eliminates the risk of a burst pipe, water damage, and emergency weekend service rates.