A few weeks ago our family noticed water coming out of the cabinets around the kitchen and bathroom sinks. With a little inspection, we found that the same issue in each case was to blame. The pipe in the U-trap was leaking due to being worn out from years of use. The pipe, as its name indicates, is U-shaped.
The importance of the U-trap in addition to keeping your floor dry and getting rid of water is that because there is some water at the bottom of the pipe at all times, this helps prevent sewer gases from entering your home and harming you or your loved ones.
After diagnosing the problem, the next step is to go to the hardware store and get a replacement. In addition to a flashlight (no matches or open fire source!), you’ll need a pipe wrench (only if you can’t use your fingers to remove the nuts holding the pipe in place) and a spare pipe (either metal or PVC). You should check the pipe to see if you can remove it without a wrench, which will save you some money if you don’t need one, as long as there isn’t one in the tool kit. A word about pipe wrenches: You know the number they give, like 18″? That refers to the length of the handle AND the total open width of the wrench jaws. Confusing, huh? Just make sure you pay for what you need.
After you get what you need from the shop, unscrew the collars or nuts around the pipe, wiggle it slightly to see if it will budge, then pull it out of position and insert the new pipe and appropriate fittings. See that it is safe. Turn on the water. Check for leaks. If you no longer have problems with leaks from the same source, recheck all the pipe connections for the U-pipe and the P-pipe. The P-pipe is the one that runs from the U-trap pipe to the wall pipe connection, which, as the name suggests, is the pipe that leads to the wall and from there to the sewer.