Whether kitchen or bathroom, fixing a sink can be straightforward or it can be a nightmare. Much depends on the condition of the valves and hoses leading to them.
In most cases do-it-yourselfers can shut off the water valves under the sink with a few clockwise twists. But if those valves are old and have never been turned since they were installed they can break, causing a leak.
Be prepared by having a partner stand near the main shutoff valve with a walkie-talkie ready to turn off the water to the whole house.
Main shutoff valves for most tract homes are near the curb, covered by a cement lid with a small rectangular hole. The hole allows public utility workers to lift the lid with a small metal rod with a hook at the end. But they can usually be lifted with a finger.
Rural homes often have a well house or other exterior assembly where the main valve is located. Locate it before you get started.
Once the water is shut off, there can only be a small amount of spill from any remaining water in the hoses and pipes. Clear the undersink area and put down a few towels flat and have a pan at hand.
Undo the connectors. These can be brass nuts or small tin clamps or smaller versions of the screw clamps that attach car radiator hoses to the water pump and radiator. The variety is extensive.
Examine the valves and hoses and replace as needed. In theory that’s straightforward. Buy replacement parts and be sure to get plenty of Teflon plumbers tape. In practice a few things can go wrong.
In rare cases, older valves may need to be cut off with a hacksaw or small torch. In very rare cases, older valves were welded on. Replace with the threaded type. Try to leave enough pipe to re-thread, using a rethreading tool. At this stage you will begin to think about paying a plumber. Your call.
Valves and hoses that have been in place for several years will usually have some calcium carbonate build up. That’s the white, chalky substance that forms on the surface of cups in the bathroom or shower stalls.
It’s usually the guilty party when things stick, but can often be loosened with a few sharp twists. Try not to tug hard, since that can pull pipes loose or cause breaks. Once broken, pipes have to be re-sealed or replaced. Either is usually an unhappy chore since the breaks tend to be where you can’t get at them easily.
Once everything is removed, clean the surfaces well with fine sandpaper and/or steel wool, sponge, etc.
Now for the (relatively) easy (but definitely tricky) part. Wrap several layers of plumbers tape to the threaded and smooth surfaces where valves and hoses will be replaced. Most important: remember to thread the tape in the direction in which the valve or hose will be turned. You want to tighten the tape when screwing on the valve or hose, not loosen it.
Screw on the valve, attach the hose and tighten any clamps. Don’t over tighten. Things need to be snug, but not to the limit of your wrench.
Turn the valve on slowly, a couple of turns, looking for leaks. If you’ve done the job carefully, the combination of well fitting threads and carefully laid tape will be fully sufficient to prevent leaks.
Sometimes two or three tries is necessary to get the hang of the technique. One of the reasons for not over tightening the valves. Don’t be frustrated if you have to take it off and re-do. It’s typically only a once in several years job.