The method for repairing a plumbing leak depends on the nature of the leak in question. Serious leaks may require a professional plumber, but often, home repair techniques are sufficient to deal with a plumbing leak. Any plumbing repair job will begin with identifying the problem. To repair the leak, you might be able to use waterproof tape or a plumbing repair kit from a hardware store.
If a plumbing leak occurs at a joint, simply tightening the joint might be sufficient. For a plumbing leak at a threaded joint where one piece is screwed into another, a pipe wrench should be used to tighten the joint, hopefully stopping — or at the very least slowing — the leak. Care should be taken that tightening the joint at one end of the pipe does not loosen the other end, creating a new plumbing leak.
Not all pipes, however, are screwed into place, and tightening might not be an option. When threading or screwed-on fittings are not visible, or when signs of welding are present, tightening is not an option. Copper pipes are joined by a process called sweat welding or brazing, which is best left to professionals.
A pencil and tape might be sufficient to repair a small pinhole leak in a pipe. By snapping the tip of a sharpened pencil in the hole, the plumbing leak is plugged. Similar plugs or an epoxy paste also can be used to plug the hole. The leak is then wrapped in several layers of waterproof tape to keep the plug in place. It will be necessary to keep a close eye on this patch, and if the leaking continues, further steps will need to be taken.
Home repair techniques can be used to stop larger plumbing leaks as well, at least temporarily. Many hardware stores stock plumbing repair kits. Most of these kits contain a rubber pad and a set of clamps. The pad is placed over the leak and held tight by the clamps. This should significantly slow any leak and might stop it entirely.
The same procedure can be used with simple items such as a length of rubber or garden hose and some hose clamps. Slitting along the length of the hose makes a rectangular patch that will fit easily on the pipe. Three or more hose clamps will be needed to hold the patch in place, depending on the size of the leak.
Assuming that the pipe is otherwise sound, this patch might be sufficient to permanently stop the leak. Leaking pipes, however, often are prone to developing new leaks, and a plumbing patch is best viewed as a temporary measure. For a long-lasting solution, a plumber might be required.