I am wanting to install water line for ice maker. Problem(s): finished basement ceiling. I do not want to cut a hole in the drywall not knowing where the water lines are located. There may be water lines in wall behind refrigerator leading to upstairs bathroom but I am not sure. How is the best way to approach this?
There are stud/water line/electrical finder combos out there, but I've never used one so I don't know how effective they are.
Your best bet is to use a utility knife + a level and score the drywall horizontally in the area that you think the water lines are. Use successively deeper cuts, and the level makes the lines nice and straight, until you break through. The water lines should be halfway inside the wall cavity and therefore should not burst, unless you decide to use a sawzall or sledge hammer.
Make the hole wide enough so it ends up halfway, or 3/4" on the adjoining studs. That makes the drywall repair easier.