Dealing with Corroded Copper Wires

Posted on: 22 July 2016

Although water and the electrical wires in your home should never cross paths, it happens. Water splashed from a tub, a flood, or a leak in your roofing can introduce water into your home. If that water finds its way to an electrical wire, this will not necessarily cause a short, but it will cause corrosion. If you have corroded wires in your home, you need to know how to deal with them. 

What Is Corrosion?

When copper is exposed to water, it will begin to devolve into metal salts. This process is known as corrosion. Unlike fresh copper, corroded copper is not a good conductor of electricity.

How to Recognize Corroded Wires

A fresh copper wire will be bright, like a new penny, and pliable. On the other hand, corroded copper will range in color from dull brown to Statue-of-Liberty green. It will also be brittle and prone to breaking. The corrosion on the wires acts like an insulator, so if you have any outlets, switches, or fixtures that stop working after a flooding event, you should take that as a sign that you might have corroded wires. 

Dealing with Corroded Wires

When you find that you have corroded wires, you need to start with the least invasive approach to dealing with the problem and proceed to the most drastic approach as needed. Follow these steps:

1. Turn off the electricity to the circuit in question at the breaker.

2. Remove the fixture. Inspect the fixture's wires. If they are corroded, you will have to replace the fixture. 

3. Inspect the wires extending from the wall or ceiling. The exposed ends of the wires will corrode first. Start by brushing the wires with a metal-bristle brush. Sometimes only the outer layer is corroded, and in these cases you can save your wires by exposing the unaffected core. 

4. If brushing the wires does not work, try cutting off the ends of your wires and stripping away about an inch of the plastic sheathing to expose fresh wire. 

5. If the first inch of newly exposed wire is corroded, cut it off and strip away another section of wire. Proceed thusly until you expose wire that has not yet been corroded. 

6. You should have several inches of wire in the electrical box to which your fixture attaches. If all of this wire is corroded, you will need to snake a new wire from the next fixture down the circuit to the electrical box you are working on. This step will most likely require an electrician. 

7. Once you have removed all corroded wiring, wire a new fixture and secure it in place with its mounting screws. 

8. Turn the circuit in question back on at the breaker. 

If the wires in your home are not too badly corroded, you should be able to make your own repairs. On the other hand, if you are not comfortable working with electricity, you can call in an electrician in your area to make the repairs for you.