When should I replace my galvanized steel pipes?
Tuesday, February 4, 2020
The average lifespan of galvanized steel water supply pipe is 40 to 60 years. Galvanized pipe was gradually phased out of new construction during the 1960s and not used at all for new homes by the mid-1970s. So any galvanized pipe still in place is at, or very near, the end of its serviceable lifespan.
Corrosion is the culprit that shortens its serviceable life, and the pipe literally rusts from the inside out. Loose rust particles collect behind faucets and reduce water flow at fixtures over time, causing a plumbing version of arteriosclerosis, as shown in the photo below of the end of an abandoned galvanized steel pipe that has been cut off behind a washing machine faucet.
If your galvanized steel pipes are over 40 years old, here’s several ways to tell when it's time to change them out:
•• Low water flow at faucets - The rust particles that collect behind the faucets in your home over time will cause what seems like low pressure at the sinks and tub spouts, especially when you first turn the water on.
•• Pressure differences between fixtures - You might find, for example, that the bathroom sink is fine, but water flow at the bathtub is low. Alternately, a common sympton is that the flow at the bathroom sink drops to a trickle when the bathtub is being filled.
•• Rust discoloration of water - You will notice this when you first turn a faucet on that hasn’t been used for several days. There will also be occasional rust flakes in a glass of water.
•• Leaks - A problem called “galvanic corrosion” occurs with galvanized pipe any time there is copper nearby in the system, such as at a water heater. It’s a crumbly cancerous growth that eventually causes leaks. To learn more about it, go to our blog post What's that powdery crust on the pipe connections at the water heater? Ordinary rust can also progress far enough to cause leaks. The place to look is at shut-off valves under sinks, at toilets, and above the water heater, especially at the wall penetration. Here’s a few examples below of both rust and galvanic corrosion.
If you are not sure if your pipes are galvanized steel, see our blog post How can I tell what type of plumbing pipe I have?
It is possible, however, that although you see galvanized steel pipe coming out of the wall at your plumbing fixture, you may have copper piping with galvanized nipples. An example is shown below at a wall where a galvanized steel nipple in a copper pipe system was recently replaced, but the wall opening was not repaired yet. To read more about it, go to What is a galvanized nipple?
If you see any of the above symptomes, a plumber can advise you about how urgent it is to replace your pipes. There are multiple choices for replacement pipes, but the most popular today are CPVC and PEX.
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Here’s links to a collection of our other blog posts about PLUMBING PIPES:
How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manfuactured and modular homes
for Links to Collections
of Blog Posts