Kitchen and bath remodels in houses built on concrete slabs offer their own unique set of challenges, not the least of which is tying the new drain system into the home’s sewer line. Cutting into the slab at the precise location will keep the schedule in tact and costs down. But how do you go about finding that location? Contractor Ron Paulk reaches for a Pipehorn, a device that emits a signal through the line that can be read by a wireless receiver.

Paulk starts by running a fish tape through the line, which he then hooks up to the Pipehorn transmitter. Next, he tunes the frequency of the receiver, then uses it to trace the path of the pipe – which he says he can do within 1-in. in either direction of the line.

Early in this video Ron makes the important point that if you only need one of these on occasion, it’s probably best to rent one as they can run about $1400.

Watch Ron demonstrate this process here: