How to Fix Leaking Plumbing Lines

How to Stop Leaking Plumbing Supply and Drain Lines

By Mark J. Donovan

Question: Mark, I’m an American expatriate living over in a country where the plumbing workmanship is shoddy at best. I moved into a new apartment, and all of the plumbing supply and drain lines going to and from the sinks and toilet leak. The leaking plumbing lines seem to be coming in all cases from where the hoses connect to the sinks and toilet. I’ve replaced the rubber sealing rings, but the leaks still persist. The “nuts” can’t be tightened any more than I have already. What do I do? I have to keep all of the water supply valves turned off until I need water.

Then I have to mop the floors afterwards. Is there a sealant that I can use to fix leaking plumbing lines? Keep in mind where I am living plumbing supplies are not readily available. Please help. Thank you. WT

Answer: WT, I can relate to your leaking plumbing line problems. I have had similar issues in hotels in various locations around the world where the sinks constantly leak and the toilets continuously run.

To answer your question succinctly on how to fix leaking plumbing lines, I would suggest finding some Teflon plumbers tape. Plumbers tape is a thin white tape that is used to lubricate plumbing threads and to improve the water tightness of a plumbing joint. Plumbers tape is very inexpensive and you can usually find it at any hardware store. It is a very basic and ubiquitous plumbing supply product. I would think you could find plumbers tape in almost any country, including most third world countries. How to fix a leaking plumbing supply line.

You can use plumbers tape on both supply and drain lines. To use plumbers tape, unscrew the fittings and wrap the male threads with the plumbers tape.

Make sure not to wrap the plumbers tape over the ends of the male fittings as this could reduce water pressure to your plumbing fixtures. Then screw the fittings back on. You should notice that they are tighter to fit. When wrapping the fitting with plumbers tape it is best to wrap the tape in the direction of the threads.

This will prevent the plumbers tape from coming unwound or bunching up when you screw it into the female end of the fixture.

As an alternative to Teflon plumbers tape you can also use pipe dope. Pipe dope is a pasty like material which performs the same functions as Teflon plumbers tape.

Also, if it is the drain lines that are leaking, which sounds like it is not your case, make sure that there are plastic compression fittings where you tighten up the plastic or metal nuts. In addition, make sure the drain nuts and the connecting drain pipes are not stressed or cocked sideways in anyway.

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For example as the plastic or metal sink drain pipe shoots down underneath the sink, make sure the receiving end of the connecting plastic or metal P or J trap is lined up directly underneath the sink drain pipe. If they are not perfectly lined up there can be stresses at the nut area that may cause leaks.

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