Ask The Expert

Hi Robert,

I had a leak in my bedroom. It started out as a little stain then kept going until the ceiling was dripping. We are retired and on a fixed income so I was not looking forward to paying for a plumber to come out, but then I thought I’ve been reading your column for over a year now and can do this myself, right? I feel like a contractor. So I turned off the water, opened up the wet drywall, and pulled out all of the wet insulation. I have two ¾” galvanized pipes running up above there. I didn’t see where it was leaking so I thought I’d turn the water back on very slowly to get it leak so I could fix it. I turned the water back on, but no leak. This is very strange because the ceiling was dripping, now nothing. I don’t want to get the ceiling back up and then have it start leaking again, but I don’t know what to replace. Any comments at all would be greatly appreciated,

Henry T.

Hi Henry,

It sounds like when you turned the water back on, it flushed some sediment through the pipe and sealed the leak, temporarily, from the inside. I would not trust this to hold too much longer and would not replace the ceiling until I knew the repair had been made.

The area directly above the damage to your ceiling can be an indication of where the leak is located, but not always because water will travel. Are the pipes level? Could it be leaking further up the line and running down? If you’re not sure, replace everything that might be leaking to be on the safe side.

If you replace the galvanized with copper, remember to transition with a brass nipple because if you connect copper directly to the galvanized they will corrode. This is known as galvanic corrosion. One of the pipes becomes the anode, the positive side, and the other acts as the cathode, the negative side. When you connect two different metal pipes to each other they create a positive difference and exchange ions creating a small electric current. The water flowing inside the pipe is the electrolyte – since basically all water is slightly acidic, so what you’ve done is made a battery.

You can also use dielectric couplings, connected to the galvanized, with the copper in between. The dielectric coupling has plastic in the middle which acts as a shield so that the two dissimilar metals don’t talk to each other. You would thread that onto the galvanized side, and sweat the copper to the other side.

Mr. Lamoureux,

I had a leaking shower head and called a handy man to fix it. He replaced the cartridge but now hot water comes out of the cold side and cold water out of the hot side. He said he was going to come back but didn’t. How can it be repaired? Thank you,

Jeri C.

Hi Jeri,

The cartridge was put in backwards so what you have to do is valve down the house or building, pull the cartridge and reset.

Basically it’s just a stem with holes on top called ports which got reversed.

Robert Lamoureux of IMS Construction, Valencia, CA, has 30 years experience as commercial General, Electrical and Plumbing contractor. The opinions expressed in “Your Home Improvements” are not to replace the recommendations of a qualified contractor after a thorough visual inspection has been made.

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