: We are remodeling our kitchen. We had our terazzo floors cleaned and our hot water pipe was hit by the polishing machine and is leaking under the terazzo. We are trying to reroute the line so that we dont have to tear up our floor. How do we know which copper pipe is the one that needs to be replaced?First of all, if you had your floors cleaned by a professional who charged you money for it, have them fix the problem they created. They are responsible for damages. Second, if it was a free job, youre going to have to fix it yourself. First, find all likely lines in the area. Eliminate all that you can positively identify. Tag them so you dont forget them. Try running the hot water through the offending line. It will be much hotter to the touch than other lines, even if they are hot water lines. Do not run hot water in any other line for an hour or so of doing the test. That allows the other lines time to cool off. You can also have one person tap on the offending line while another person feels all the possible lines for vibrations. If the lines connect or touch, this will only eliminate some of the possibles. Look for valves which may shut off the water to the offending line. Try shutting off valves until you find one that works. Doing all of the above will probably single out the line that you seek. Or any one might prove a positive method. Its a time and trial and error thing with a lot of older homes. But persistence pays. Good luck to you.