Frozen Pipe Solutions

[Art Maydan]

Does anyone have experience installing heated pipe tape in units that have already been built and are occupied? Last year when it hit -40F, we had several units with frozen pipes running along exterior walls freeze despite dripping water. I was running around in snow pants trying to find a store with space heaters still in stock and setting them up to heat the walls to prevent them from bursting. None burst thankfully.

I want to install electrical heated piping tape around those pipes, but I've had two plumbers now tell me they'd need to cut open the whole wall to find the pipes and cut through bathroom tile and it would be a huge job and they don't want to do it. Can't you just use some sort of stud finder to find the pipe, or at most cut a couple exploratory holes and stick a camera in there, open up the wall along intervals, and do it that way? Are there better solutions I'm not thinking of?

Much appreciated