Galvanized Piping in Old Homes

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Galvanized Piping in Old Homes - uvengwa - old-house-52.jpg

When I worked with my father rehabbing old houses, one thing I learned was that electrical and plumbing are two of the most difficult aspects of reviving an old structure. But my father did much of the work himself when it came to plumbing and electrical, and he was especially skilled at getting old plumbing working again without relying on a plumber. Restoring old plumbing can be a tough project, and the amount of time you spend on the location of the pipes, and the types of pipes you're dealing with.

What are galvanized pipes?

Galvanized pipes are made to last for multiple decades, but they can wear over time if "hard water" has been circulating through the pipes. The zinc coating on galvanized pipes provides protection for outside pipes, and to insulate the networks from indoor humidity. However, because galvanized pipes typically have threaded fittings, this can cause leaks if not properly installed, and minerals inside can build up inside the pipes, causing blockage. Old pipes from the pre-1960s were made from galvanized steel, which is why replacing old plumbing in a house is so common.

When it comes to check on the plumbing of an old house, turn on the hot water to see if the water is low. This is usually a sign that the pipe is either corroded or clogged. This is not necessarily a sign of pressure problems, but galvanized piping could be the issue.

Handling Galvanized Pipes

There are two methods of dealing with galvanized piping, one is to replace the entire system, and the other is to replace only bad sections of the system. Experts will differ on this subject; some say it is best to replace the entire system to prevent reoccurring problems, but you can also replace problematic sections. When it comes to this issue, there are trade-offs. If you choose to replace the entire system, you will deal will the problem entirely, but it can be expensive. Fixing only bad sections of plumbing is less costly, but there is the added problem of locating the defective section. You may need to replace the old piping with more galvanized piping, since using other pipes like copper can cause problems. If using copper, for instance, you'll need to use dielectric couplings to prevent corrosion between two types of metal.

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Connected Copper and Galvanized Pipes

Finding Bad Pipes

Let's say you want to get rid of the bad portions of the system. The problem can be difficult to locate, especially if the pipes are behind the walls, but looking under the sinks is a good place to start, since plumbing is often run underground. If you have a crawl space, look under there as well. The problem can also be in the sewer line.

Scouting In the Sewer Line

Anything on the house portion of the meter is the homeowner's, while the street side belongs to the city. You can find out if there is a leak by turning off the water inside the house and checking the meter. If the dial still moves, you'll know you have a leak. You can rent a sewer camera to check on the supply line, and it costs anywhere from $100 to $200, depending on where you are, and how long you want to rent it. This is the most direct way of checking for signs of blockage like root penetration, garbage, etc. You may also find damaged pipes in the process.


If you find that the problem is blockage, make sure the problem can be remedied with the proper drain cleaner. However, you must be very careful when using drain cleaner, since oxidizing agents in the cleaner can eat through not only the gunk, but the pipes as well, especially older, galvanized pipes. You can use an enzyme-based drain cleaner as a safer try, and/or use a plunger or auger to unclog the pipe. Also, vinegar and baking soda left to sit overnight could work as well. If that does not work, then there may be physical damage involved, in which case you'll have to locate the damage. The best way to do this is to search the piping throughout the house and check for signs of damage. A damaged pipe is easier to find, since you can see the damage firsthand. If you have damage, your options are to replace the bad section with pipe cutters and a new piece, or you can replace the pipe entirely. There are also temporary measures that can be taken, as shown in the video below:

If you opt to replace to replace the system, stay tuned for my next piece on digging deep and replacing the entire structure.

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