Drilling into water lines takes place within walls, beneath concrete foundations, and in perimeter ground soil most often during termite treatments. Damage to water lines in attics takes place most often during inspections or attempts to set traps for vermin. The key to avoiding damaging water lines in both situations is proper planning. Know the job risks before beginning the work and plan to avoid the common water pipe hazards.

Within the Walls
Are you ready to treat for active infestation but don't know where the water line runs behind the wall?  Rest assured that if the room behind the wall is a bathroom, kitchen, laundry room, or other room where water enters or leaves there is a high probability of finding a water line behind the sheetrock. The key is to find the line, or verify its absence, before beginning to drill.

The use of a simple physician's stethoscope may be the most reliable method to verify a water line without having the home building plans. First turn a faucet closest to the wall where drilling needs to take place on low, and if possible the faucet turned on should be on the opposite side of the wall from where the street side main is located. While water is flowing, place the stethoscope along where drilling is necessary. The sound of water through the stethoscope will be louder as you get closer to the pipe. plumbers have been using stethoscopes to detect hard-to-find leaks in pipes for years. Although hot and cold water pipes usually run close together, both faucets should be turned on to improve chances of locating the pipes. (Stethoscopes can be purchased on the internet for as little as $7.00 and as much as hundreds of dollars.)

Another method, although less reliable, is the use of battery-powered stud finders. Basic construction knowledge that wall studs are commonly located either 12", 18", or 24" apart (referred to as distance "on center") is helpful if using a stud finder to search for water lines. First find the studs by running the stud finder along the wall until it gives off the clearest signal indicating a solid wall stud. Find the adjacent stud using the same method of sliding the stud finder along the wall. Once locations of adjacent studs is confirmed, use the device between the studs, this time searching for "shadows" or signals similar to a wall stud but not as strong. (Practice this method on walls where you know the location of pipes.) Mark the area where you suspect water lines with a piece of tape and avoid drilling in that area. Keep in mind pipes run both vertical to the wall studs and perpendicular when leading to an outlet.

If you're on a job and don't have a stethoscope or a stud finder, you will need to rely on basic construction knowledge to avoid water lines. Sheetrock or gypsum wall board comes in two basic widths: 1/2 inch and 3/4 inch; the higher construction quality, the thicker the drywall. Mark your drill bits at both 1/2 and 3/4 inch from the tip. As you drill into the wall, stop when you get to the first mark and see if the wall has been opened to the cavity. Repeat the process at the second mark if the wall board is thicker than 1/2 inch. When the wall cavity is penetrated, stop the drilling. Most pipes run in the center of the wall cavity and are NOT touching the drywall. You are relying on this construction feature to avoid the pipes. Careful drilling to the point where the drywall is penetrated and no more will avoid many water strikes.

Beneath Concrete
Concrete foundations are poured in place over water supply lines to homes. Unless you have a copy of the home plans, it can be difficult to know where a water line is located beneath concrete foundations. When drilling into concrete to treat for active infestation of termites, the goal is to reach the soil but not penetrate into the soil too deeply. Avoid putting too much pressure behind the drill, which can cause deep penetration of the bit into the soil, increasing the potential of striking water supply lines. Using a sharp drill bit designed for concrete is the best way to maintain a controlled drilling.

Perimeter Ground Soil
Many water line damage incidents take place when operators are digging perimeter trenches around houses where termite barrier treatment will be applied. If power equipment is used to dig, these trenches care must be taken to stop the digging where water lines entering the house can be present. Hand tools should replace power tools in these areas. A common entrance of water supplies to homes is where water heaters are located. If you find the water heater and look along the wall adjacent to it, you may see a pipe coming from the outside with a water supply shut-off valve. When digging the trench around the house outside this room, only hand tools should be used.

Attics
Avoiding water pipes in attics should be much easier than avoiding hidden lines in walls, under concrete, and in the ground. The key to attic loss prevention is handling the job cautiously. When first entering the attic, the operator should attempt to identify where water lines are located keeping in mind that they are often laying on top of joists hidden by insulation. A reliable flashlight and a lightweight long thin stick are valuable tools for locating water lines to avoid in attics. (Retired lightweight fishing rods are perfect for this purpose.)

Identifying water pipe location is half the battle. The other half is staying as far from the lines as possible. Lightweight walking boards are excellent for providing a solid standing area in attics. When setting traps, operators need to be prepared to remain calm if suddenly surprised by squirrels or other critters while in the attic. There are claim incidents that involve pest control operators falling through ceilings. Depending on potential for injury, some of these claims can be more severe than striking water pipes.