Slab & Copper Pipe Repair

Testing for and Locating Leaks

• A simple two-step test is commonly performed to check for a leak. First, a pressure gauge is attached to an open spigot. All water usage is then halted, allowing the gauge to register the pressure at which the water is delivered from outside the premises. Second, the water meter is shut off. Any subsequent drop in pressure indicates a leak. Water outlets such as faucets and toilets are checked for drips or slow use -- for example, a running toilet -- and if no leaks are found, a leak under the foundation is determined to be the most likely cause. Locating the leak is usually done either through small cameras inserted in the pipelines or electronic listening equipment that can identify anomalies in the pipe's sound pattern.

Methods for Pipe Removal

• Once the location of the leak has been identified, that section of pipe must be isolated and removed from the slab floor. In order to do this, workers must cut into and remove a section of the concrete directly above the pipe. Then, the area must be carefully excavated, digging out the soil around the affected pipe while ensuring not to cause any additional damage. In rare instances, the pipe is already exposed somewhere under the foundation and is easy to access, making the cutting and excavating unnecessary. Next, the workers remove the pipe by cutting at least 1 inch on either side of the leak using a pipe cutter or circular saw.

Epoxy Repair

• The first major method of repairing a copper pipe is through an epoxy. This method is more commonly used when the leak is smaller. First, the pipe must be thoroughly dried and cleaned with a solvent so that no traces of dirt or oil remain. Next, a two-component epoxy is mixed with water and applied to the surface of the pipe over the leak. Many water-based epoxies are specifically designed for metal-based, industrial-strength applications where maximum holding power and water resistance are essential. The epoxy is then allowed to harden for an hour before the water is turned on and the repair confirmed. Epoxy putties are also available for extra-small pinhole leaks.

Solder Repair

• The second major method of copper pipe repair, soldering, is more practical for larger leaks. First, a copper repair sleeve slightly thicker than the pipe must be cut to a length approximately 1 inch longer than the area of pipe that was removed. The inside of the sleeve is thoroughly cleaned with a wire brush and the outside with emery paper. The sleeve is fitted onto one end of the pipe, then the other (with some flexibility in the pipe necessary) so that a half-inch of pipe sits in the sleeve at either end. Solder wire is wrapped around one sleeve joint and melted with a blow torch. The process is then repeated on the other joint. After the solder has cooled, the water can be turned on and the repair confirmed.