Last Update: Thursday, April 17, 2014

Find and Repair Water Leak Underneath Kitchen Sink PDF Print E-mail
Written by Pat Logan   
Friday, 27 December 2013 23:03

Dear Pat: I was cleaning some old things from under my kitchen sink and I noticed the bottom of the cabinet was damp. I could not see a leak, though. Where should I check, and how can I fix the problem? -- Stacey L.

Dear Stacey: If your cabinet under the kitchen sink is like most families, it becomes a catchall for every can or bottle of cleaner, polish, etc. With all the stuff in there, a leak can go unnoticed for months or years. If the cabinet floor stays damp, it will surely rot and become moldy. If your house is built over a basement, anything stored below it may also be damp.

If you are lucky, the source of the moisture may not be from a water leak at all. A bottle or can may be leaking slowly. When cleaner leaks, it does not dry as fast as a water-only leak. Place the cans and bottles on your countertop and check for damp spots around them the following morning. Assuming all the cans and bottles check out fine, there are three typical sources for the dampness under a kitchen sink. The first is the hot and cold water supply lines or fittings, which attach to the kitchen faucet. This water is always under pressure, so any flaws result in leaks. Since water flows to the lowest point before dripping from a pipe or fitting, it can be difficult to find the source of the supply line leak.

Try this technique: Turn off the supply line valve to the hot water line. Wipe the entire pipe and fitting with a paper towel to make sure it is dry. Wrap a piece of tissue paper around the pipe and fitting. Use rubber bands, tape or twister seals to keep it in place. Turn the hot water supply line valve back on again. If there is a leak, you will be able to easily see where it makes the tissue get wet first. Repeat this procedure for the cold water line.

The next place to check is the seal around the faucet fixture where it fits on top of the sink. Many thin stainless steel sinks tend to flex downward around the heavy fixture. This causes water to puddle around it. If the faucet was not sealed properly with plumber's putty, water can leak under the fixture into the cabinet below. This is relatively easy to fix if the fixture is not too old. It just requires the fixture mounting nuts to be loosened to allow the fixture to be lifted up a little. This should provide enough clearance to install a new bead of putty.

If it is an older fixture, there is a good chance the nuts are rusted on. Take your time; otherwise, you can break the fixture. If everything checks out so far, the drain or trap may be leaking. Even though PVC plastic pipe is durable, the trap hanging down beneath the sink can easily get damaged. Metal traps are less prone to damage from impacts, but they do rust out over time and begin to drip. Wrap a tissue around the drain and trap next time you empty the sink, and check for leaks. If you replace a leaky trap, install a Y-fitting for a cleanout.

Last Updated on Friday, 27 December 2013 23:07

viagra generic