Three systems in every house
Every home plumbing system is really three systems sharing the same walls. The supply side brings pressurized water in from the city main or your well, through the meter and main shutoff, then splits into cold lines and a line to the water heater. The drain-waste-vent (DWV) side carries used water out by gravity, through traps that hold a seal of water against sewer gas and vent pipes that poke through the roof so drains flow smoothly. And the fixtures and appliances sit between them: sinks, toilets, tubs, the washer, the dishwasher and the water heater.
Knowing which side a problem lives on tells you a lot. Supply-side problems are under pressure, so they leak fast and need the water shut off. Drain-side problems don’t leak until something is running, then they back up, gurgle or smell.
What’s inside an older Lancaster home
Galvanized steel supply pipe. Common in homes built before the 1960s. It rusts from the inside, so water pressure slowly drops and the water can turn brown after it sits. Repiping with copper or PEX is the long-term fix.
Cast-iron drains and stacks. Strong and quiet, but after 80 or 100 years the bottom of horizontal runs can rot through, and the inside gets rough enough to catch every clog. See drain cleaning.
Clay or Orangeburg sewer laterals. Clay pipe joints let roots in from the street trees that shade so many Lancaster blocks. Orangeburg, a tar-paper pipe used mid-century, collapses with age. Our sewer line guide covers both.
Lead. Homes built before 1986 may have lead solder on copper joints, and the oldest homes can still have a lead service line from the street. If you’re not sure, ask your water supplier and have a plumber check the pipe where it enters the basement.
Repair or replace?
A dripping valve, a cracked trap or a single failed fitting is a repair. Replacement makes sense when the same pipe keeps leaking in new places, when galvanized lines have choked the pressure down to a trickle, or when a camera inspection shows a sewer lateral that’s broken in several spots rather than one.