Pro Handyman Blog

A plumbing leak at a drain can be coming from several areas. Grab a flashlight and start looking for the source of the leak. Just because the water is dripping off the lowest pipe sure doesn’t mean that it is the cause of the leak. Run the water and look for the source. If the leak is occurring 24 hours a day, the leak will be coming from a pressurized water line or valve.

If the leak occurs only when the water is running, then the leak is probably somewhere on the drain line. Check along the drain line for where the leak is originating. It will likely be at a slip fitting which you may need to tighten or replace. If that doesn’t stop the leak, unscrew the fitting and check the slip washer. These have a tendency to crack which won’t allow it to stop the water. Replace it and tighten.

If the source of the leak is coming from where the drain connects to the sink, you will have to remove the drain assembly. In many cases, the installer will have used silicone under the drain flange. Silicone needs to set up and even then, I don’t have as much confidence in it as I do plumbers putty. My choice is to use plumbers putty under the flange. Roll out a chunk about as thin as a pencil and push it under the flange. As you tighten down the drain assembly, you should see it ooze our around the flange. That is a good thing and confirms you have good coverage.