What To Do About Leaks In Water Pipes. Leaks can occur in water pipes where the pipe is screwed into a threaded joint. There is no actual break in the pipe, but the sealing compound in the joint may have dried out. Leaks also occur if the pipe is broken or cracked, or might happen from expanding ice in the pipes. In any case, you must correct the defect quickly to prevent water damage.
If the leak is easily apparent, you will know whether water is leaking from a joint or from a hole in the pipe. If the pipe is inside a wall and your first sign of trouble is water leaking on the floor or a damp wall, you will have to rip open a partition in the wall to determine the source of the leak. Don’t be afraid to do this, since a plumber would have to do it anyway before he could fix the pipe. Inspect both sides of the wall to determine which can be opened with a minimum of damage. In any case, whether the leak is in the open or hidden in the wall, your first step is to turn off the water in the pipe.
If the leak is at a threaded joint, you can sometimes stop it simply by screwing the pipe farther into the joint. To do this, you will need two wrenches, one to hold the joint and the other to turn the pipe. If you use only one wrench on the pipe itself you may twist the joint and cause a break in the pipe, on the other side. Note that when you screw the pipe into the joint, you will be unscrewing it from a joint at the other end. Nevertheless, sometimes a quarter of half turn may be enough to stop the leak without causing trouble at the other end.
You can also seal the joint with an epoxy patching material, available in most hardware stores. Full directions for mixing and applying the chemicals are given on the package. The most important step is to make certain that the surface of the pipe is clean and dry before applying the patching compound. The same epoxy compound can also be used to seal small holes and cracks in pipes. The compound should be allowed to harden for about twelve hours before the water is turned on again.
Ordinary pipe sealing compound can also be used to cure a leaking joint. Unscrew the pipe, coat the threads with the compound, and then screw the pipe back into the joint. Again, as you unscrew the pipe from one joint, you screw it onto another at the other end of the pipe. To seal both joints, first unscrew the pipe at one joint and coat it with compound. Then screw it back far enough to unscrew the other end and coat that end also. Finally, screw it back into the second joint so that it goes approximately the same distance into each joint. If you want to reinforce the joint, you can wrap fine cotton thread or string around the threads on the pipe after you coat it with the pipe compound. The string swells when wet and acts as an additional seal, although, in most cases, the pipe compound alone is sufficient.
If the leak is in the pipe itself, it can be fixed with epoxy compound. For larger leaks and cracks, patching kits are available, consisting of fiberglass, cloth, which is wrapped around the pipe, and epoxy compound, which is applied first and then again on top of the fiberglass. This type of patch is permanent and should outlast the pipe. Again, the most important step in putting on the patch is to make sure that the pipe is clean and dry.
Unfortunately, leaks usually happen on weekends or at night when hardware stores are closed. If you have no patching material, you can make a temporary repair. A piece of rubber, such as a strip from an old inner tube, is held against the leak with a C-clamp. After the hardware store is open, you can buy a patching kit for a permanent repair. Stores also sell pipe clamps and plugs for sealing small leaks. These work on much the same principle as the C-clamp. The advantage of the clamp over the epoxy-patching compound is that the pipe is usable immediately after putting on the clamp. The clamp is supposed to be a temporary fix, but some have been in use for years.
If the pipe is badly corroded or has a wide split, it should be replaced. Use a hacksaw to cut the pipe somewhere near the middle, and then unscrew each half from its joint, using two wrenches, one on the pipe and one to hold the joint. Measure the two joints. Take one of the pieces of pipe as a sample to a plumbing supply store and explain that you want that kind of pipe to cover the measured distance (you will need pipe somewhat longer to include the thread that goes into the joint). The replacement should consist of two pieces of pipe and a union that goes between them. Each of the two pieces of pipe is threaded at both ends. One pipe is threaded into each joint, and half of the union is threaded on each pipe. Make certain that you slip on the coupling nut before you screw on the union. The union permits joining the pipes without twisting them. The two halves of the union are held together by tightening the coupling nut with an adjustable wrench. A packing gasket inside the nut prevents a leak at the union. Threading pipe is simple if you have the proper tools, but since you are unlikely to have them, buy pipe already threaded.