I have a shop that has in-floor pex at 1' centers. I don't have a heat source hooked to the lines in the floor and don't plan to for several years. I would like to drill a 4" hole in the floor, so I want to avoid the lines. I know to use an IR gun and look for the hot areas, but I don't have a heat source hooked to the lines. Any other ideas? I don't want to put hot water in the lines because they will freeze next winter.
Locating in-floor heat lines in concrete slab
