Houses plumbed before roughly 1960 very commonly used galvanized steel supply line — zinc-coated steel, robust, and entirely reasonable by the standards of the day. Olde Town Arvada and the older parts of Wheat Ridge have a great deal of it still in service.
The problem is not that it fails suddenly. It is that it closes up slowly.
What happens inside the pipe
The zinc coating protects the steel for a few decades, then wears through. After that the steel corrodes from the inside, and the corrosion products build up on the pipe wall rather than washing away. The interior diameter shrinks, year after year. A three-quarter-inch line ends up passing water through an opening a fraction of its original size, with a rough interior surface that slows flow further.
Because it happens over decades, households adapt without noticing. People learn not to run the kitchen tap while somebody is in the shower. They assume the shower head is bad. They replace fixtures that were never the problem.
The symptoms
- Pressure that seems acceptable alone but collapses when a second fixture opens.
- The shower going cold or weak when someone runs water elsewhere.
- Brown or rust-tinted water, particularly first thing in the morning or after the house has sat empty for a week.
- Hot side noticeably worse than cold — hot water accelerates the corrosion, so the hot runs usually close up first.
- Repeated pinhole leaks or weeping at threaded joints.
- Visible rust or flaking at exposed threaded connections.
How to check in five minutes
Find where the supply line enters the house — usually the basement, near the meter, on the north or west wall. Galvanized is dull grey steel and a magnet will stick to it. Copper is unmistakable by colour. PEX is flexible plastic tubing, typically red, blue or white, and is entirely modern and fine.
One caution: many older Arvada homes have been partially repiped over the years, often just the visible basement runs. Copper at the meter does not guarantee copper inside the walls. If the visible pipe is copper but the pressure symptoms are there anyway, there is very likely galvanized still buried upstream of your fixtures.
Not sure what you have?
Photograph the pipe where it enters at the meter or the water heater and send it over. Identifying supply pipe from a clear photo takes seconds, and there is no charge for answering the question.
Patch or repipe?
This is the real decision, and the honest answer depends on where you are on the curve.
Patch when it is the first failure, when the rest of the visible pipe still looks sound, and when the affected section is accessible. Replacing one bad run is legitimate and we do it regularly — there is no sense repiping a house that is not asking for it yet.
Repipe when you are on your third or fourth failure, when pressure is poor throughout rather than at one fixture, when you are getting discoloured water, or when you are about to remodel and the walls are coming open anyway. At that point every run is the same age and has lived the same life; fixing them one at a time means paying for access repeatedly and getting less time back with each repair.
What a repipe actually involves
New supply lines are run through walls, ceilings or crawlspaces to each fixture, the old galvanized is abandoned in place rather than excavated out of the structure, and drywall is opened where access requires it and patched afterwards. Most houses can stay occupied throughout, with water off for part of each day rather than the whole job.
The part people underestimate is the finishing. Cutting and repiping is the straightforward half; drywall repair, texture matching and paint is the other. Ask any quote to be explicit about where patching stops, because that is where two apparently similar prices most often diverge.
If you are buying an older Arvada home
Check the supply line during your inspection, and ask specifically whether any repiping has been done and how much. A house with galvanized still in the walls is not a house to walk away from — plenty of them are perfectly livable — but it is a known future cost, and it is a legitimate thing to factor into what you offer.
Written by the team at Arvada Plumbing Co., 5760 Marshall St, Arvada, CO. Got a question this did not answer? Call (720) 743-3832 — we would rather answer it than have you guess.