Pipes last a long time, which is why so few homeowners know how old theirs are or what they are made of. The supply lines and drains in a house were installed once, decades ago, and have been out of sight ever since. But every pipe material has a service life, and a house whose plumbing is approaching the end of it gives signs, usually small and easy to attribute to something else. This post explains how to find out what is in your walls, how long each material typically lasts, what an aging system looks like from the outside, and how to decide when replacing pipe makes more sense than repairing it.
Find out what you have
The easiest place to see your supply pipe is where it enters the house near the main shutoff, under sinks, and in the crawl space or attic. Copper is a dull orange or brown metal. Galvanized steel is gray, threaded at the joints, and often shows rust at the fittings. CPVC is cream or tan plastic. PEX is flexible plastic, usually red, blue, or white. Polybutylene is a gray flexible plastic with copper or plastic fittings and is the one to pay attention to. Drain lines are black ABS plastic, white PVC, or, in older homes, cast iron, which is heavy, dark, and often rusted at the joints. If you cannot tell, a plumber can identify everything in a few minutes during an inspection.
How long each material lasts
Copper supply lines last 50 to 70 years or more, though water chemistry and workmanship can shorten that, and pinhole leaks are the usual way they fail. Galvanized steel, common in homes built before the 1960s, lasts 40 to 60 years and fails from the inside as corrosion narrows the pipe and eventually eats through it, which is why old galvanized systems have both low pressure and rusty water. CPVC and PEX are newer and are expected to last 50 years or more, though PEX has not been in homes long enough to prove it. Cast iron drain lines last 50 to 100 years but corrode and crack from the bottom, where wastewater sits. PVC drains, properly installed, outlast the house.
Polybutylene is the exception to every rule above. It was installed widely across the Southeast between 1978 and 1995, so a home in the Columbia area built in that window has a fair chance of having it. The material reacts with chlorine in municipal water and becomes brittle from the inside, and it fails without warning at the fittings and along the pipe, often 10 to 15 years after installation. There is no repair for aging polybutylene, only replacement, and many insurers will not write or renew a policy on a home that still has it. If you find gray flexible pipe in your home, that is the first call to make.
What an aging system looks like
The signs of plumbing approaching the end of its life are the same regardless of material, and they arrive in a pattern. Leaks begin to recur in different places rather than one, because the whole system is aging together and a repair in one spot puts pressure on the next weak one. Water pressure has dropped over the years as corrosion narrows the pipe. Water runs rusty or discolored, especially first thing in the morning. Visible pipe in the crawl space shows green or white crust at the joints on copper or rust on steel. The repair bills, taken together, have started to add up. And in homes with cast iron drains, there are recurring clogs, a persistent sewer smell, or a soft spot in a floor above a drain line. Any two of these together are a reason to have the whole system evaluated rather than fixing the next leak.
Repair or replace
The decision comes down to how many more repairs the system has in it. A single pinhole leak in 30-year-old copper is a repair. The third leak in two years in 55-year-old galvanized steel is a repipe, because every repair is buying a few months on a system that will keep failing, and each failure risks water damage that costs more than the pipe. A plumber can help you make the call with a pressure test, a look at the exposed pipe, and, for drain lines, a camera inspection that shows the condition of the pipe from the inside. Whole-home repiping sounds disruptive, and it is a sizable project, but modern PEX can be run through existing walls with far less opening than people expect, and it typically takes a few days rather than weeks.
The rest of the system ages too
Pipes are not the only components with a lifespan. Shutoff valves under sinks and behind toilets seize after 10 to 15 years of not being turned. Rubber supply hoses on washing machines and dishwashers should be replaced every five years or so, and braided steel hoses last longer. Water heaters last 8 to 12 years for a tank unit. A pressure regulator at the main lasts 10 to 15 years, and a failed one can let pressure climb high enough to stress every joint in an aging system. A plumbing inspection covers each of these along with the pipe itself, and the report tells you what to plan for and in what order.
Plan the replacement rather than react to it
2nd Wind Heating & Air Conditioning has served greater Columbia since 1985. If your home is more than 30 years old and has not had its plumbing evaluated, or if you have found gray flexible pipe anywhere in it, schedule an inspection online or through the 24/7 chat on our website. The technician will identify what you have, show you its condition on video, and give you a plan with prices, so that when the plumbing reaches its milestone, you are the one who decides when.