Water leaks are a constant hazard for residential and commercial buildings. Even small leaks can cause significant damage and lead to harmful mold problems. The first step in leak detection is to carefully inspect the building for signs of running water or water damage. If no obvious signs are found, then the owner should turn off the water supply to the building and check to see if the water meter continues to run. Once the owner has ruled out interior pipes and fixtures, he can check the water line running from the meter to the building or any irrigation lines on the exterior of the structure.
Leak detection can be a long and expensive process. While many leaks will produce visible water damage on drywall or flooring, some owners may only notice a leak on an unusually high water bill. The owner should first examine his water fixtures and areas where pipes run through the walls and floors for signs of water damage, paying close attention to lower areas where leaking water might collect. Valves and pipe fittings are common spots for leakage, as are areas where pipes can be exposed to sub-freezing temperatures.
In some instances in which the owner has noticed a high or rising water bill, one or more toilets in the building may be to blame. The owner should examine the flush and filler valves for obvious signs of wear, and listen carefully to hear if the water supply to the toilet is continuously running. Some plumbers recommend placing a bit of food coloring in the reservoir tank and waiting from 15 to 30 minutes to see if any of the dye appears in the bowl; if it does, then it indicates a leaking flapper. If the owner is unable to find the source of the leak inside the building, then he may need to turn off the main water supply.
The owner should find where the water runs into the building and try to find a cutoff valve that will completely shut off the water. In some situations the water can only be cut off at the water meter and may require special tools. The owner should make note of the water meter reading, so he can determine which side of the valve the leak is on. If the meter stops after cutting off water to the house, then the leak is in the interior. If the meter continues to run, then the leak may be in the water line that runs into the building.
In situations in which the owner is unable to find the leak, he may need to call in a plumber or company that specializes in leak detection. These professionals have equipment that can help find leaks in the walls or under the floors. While this can be an expensive process, leak detection can help prevent costly water damage to the building and stop the growth of mold that can affect the health of the building's inhabitants.