How long do water pipes last
Copper water pipes last 40 to 70 years, PEX 40 to 50, galvanised steel 30 to 50. Drains last longer still: PVC 50 to 75, cast iron 50 to 100. The parts that fail first are the small ones: taps at 10 to 20 years, shut-off valves at 15 to 30. Most 'plumbing problems' are fittings, not pipes.
Pipes are the longest-lived working components in the house, and the least watched: everything is inside walls, under floors, behind cabinets. The useful reframe is that a plumbing system is three populations on three clocks (supply pipes, drains, and fittings), and the fittings clock runs two to three times faster than the other two.
What each part lasts
| Part | Typical lifespan | What usually ends it |
|---|---|---|
| Copper supply pipes | 40–70 years | pinhole corrosion, joint failure, electrolytic corrosion |
| PEX / plastic supply pipes | 40–50 years | fitting failure, UV damage at exposed runs |
| Galvanised steel supply pipes | 30–50 years | internal corrosion, flow restriction, joint leakage |
| Taps and mixer valves | 10–20 years | cartridge failure, aerator clogging, seal wear |
| Shut-off valves | 15–30 years | seizure, seal wear, corrosion |
| PVC drain pipes (internal) | 50–75 years | joint leakage, blockage, impact damage |
| Cast iron drain pipes | 50–100 years | internal corrosion, joint failure, collapse |
| Sewer connection (external) | 50–100 years | root ingress, ground settlement, collapse |
The ranges come from the durability handbooks and trade field data behind the planning model. Read the table’s shape before its numbers: a dripping tap at year 12 and a weeping copper joint at year 55 are both “a plumbing problem,” but one is a replaceable fitting on a fast clock and the other is a system approaching the end of its slow one. Diagnosing which population is failing is most of the decision.
Supply fails wet, waste fails slow
Supply pipes are pressurised, so their failures make water: a pinhole weeps into a wall cavity, a joint lets go, and the consequential damage accumulates silently until a stain or a smell surfaces it. That asymmetry is why an aging supply system justifies planning in a way drains rarely do. Waste pipes fail politely by comparison: slow drainage, smells, a joint that seeps at low pressure. The exception is the external sewer connection, where root ingress and ground settlement work invisibly; a camera inspection is cheap next to excavating a collapse.
The valve you never touch is the one that fails
Shut-off valves last 15 to 30 years, and seizure is their signature ending: a valve that has not been turned in a decade freezes in place, discovered at the worst moment, mid-leak, when it is the one part that has to work. Once a year, turn the main shut-off closed and open again. It is the cheapest test in this guide, and it converts the valve from an unknown into a known on the exact day you need it.
When to start planning
Pieter’s house in Leiden was built in 1968 and still runs its original galvanised supply pipes, fifty-eight years against a 30-to-50 range. The shower pressure has faded for years, and the water runs brown after every holiday. That is the bore closing, not a mystery; no fitting swap fixes it. He plans the repipe for the autumn as scoped work, room by room with the floors that were coming up anyway, and briefs it with a written mandate; the Dutch plumber rate guide carries the current hourly ranges for pricing it honestly. The unplanned version of this repipe happens after a burst, with the floor open in December.
What this means before you call anyone
Name the population before naming the problem: fitting, supply, or waste. It decides whether you need a small replaceable part, a scoped repipe, or a camera survey, and it is the difference between a quote you can compare and one you can only accept. You can run repair-versus-replace for an aging supply system in the free repair-or-replace calculator. The plan in appkeep tracks the three populations as separate components with their own clocks, so the tap, the valve test, and the eventual repipe each show up as their own line instead of one emergency.
Is this a repair year or a replacement year?
You give the component, its age, and the repair quote you are holding. You see which costs less per year of service, and how much life a repair can honestly buy at this age. The method is the one property managers run: cost divided by the years it buys, not the size of the two numbers side by side.
The answer
Pick a component, its age, and the repair quote to see the year you are in.
The money is one input, not the decision. See the repair-or-replace guide for the third option (waiting, with a date) and the four times the arithmetic gets overruled: safety, energy rules, insurance, and a third failure in a year.
This runs on typical market prices and lifespans, not your own component. Signed in, appkeep runs the same method on your house's real age, cost, and history.
- Lifespans and installed replacement costs are the sourced seed behind appkeep's plan (RgdBOEI 2012 / NEN 2767, NAHB, BRE, CIBSE, trade bodies, manufacturer guidance). Prices are per unit, VAT-inclusive, in today's money. Each carries its own confidence label, shown next to the number.
- A repair does not reset the component's clock. The years a repair buys are capped by the life the component has left, and past roughly three-quarters of its life that shrinks fast, because wear accelerates. The tool reflects that in the years-a-repair-buys figure.
- The tool prices the money. It cannot see the component's condition, whether this is its first fault or its third, or a safety or insurance rule that forces the call. Those sit with you and the linked guide.
Common questions
How long do copper water pipes last?
Copper supply pipes last 40 to 70 years. Pinhole corrosion is the classic ending: tiny perforations that weep slowly inside walls and floors, often unnoticed until a stain appears. Joint failure and electrolytic corrosion (where copper meets another metal) are the other endings. Copper's age alone says little; water chemistry and installation quality decide which end of the range a system reaches, which is why a pressure test tells you more than a build year.
When should galvanised steel pipes be replaced?
Galvanised supply pipes last 30 to 50 years, and most systems still in service are already old. They fail from the inside: the zinc coating goes, then rust narrows the bore year by year. Falling pressure at the taps, brown water after time away, and repeated joint leaks are the signals the bore is closing. At that stage a planned repipe beats waiting, because the alternative is discovering the failure through a burst or a slow leak inside a wall.
Do plastic PEX pipes last as long as copper?
Nearly. PEX is rated for 40 to 50 years against copper's 40 to 70, and its design standards assume a 50-year service life. Its weaknesses are different rather than worse: fittings fail more often than the pipe itself, UV exposure degrades any run left uncovered near a window or outdoors, and it cannot be visually inspected for internal condition the way metal can. For a repipe, the material choice matters less than the installer's fitting quality.
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