Tomorrow (Friday, 12-18-09) we are performing a Peppermint Test for a customer. Our customer is getting a severe sewer odor in his basement family room and we simply cannot find it. So I remembered a test my dad told me about...The Peppermint Test. My dad was a plumber in Baltimore from the early 40's until his passing in 1982. He left me with a great many secrets of the trade...a Peppermint Test is not a secret though. It was, and still is, a recognized method of testing a plumbing drain, waste, & vent system for leaks. Here's the procedure:
Purchase an ounce or two of 100% peppermint oil (I can only find it in the pharmacy and we had to order it from a local drug store). With an accomplice on the roof of the building, boil a pot of water-about one gallon. Place the water in a thermos type container and hand it along with the oil to your buddy hanging out on the roof. Then go into the house and close all window and doors. Have your helper pour the peppermint oil down a plumbing vent pipe and follow it with the very hot water. Your helper is to stay outside the whole time. Meanwhile, you can start sniffing around the house for a peppermint odor. You will smell it if there is an air leak in the drain, waste, vent system. The odor will get stronger as you get closer to the leak. I plan to check around toilet bases, under sinks, behind the bathtubs, where drain pass through the basement floor and around clean-out plugs. This particular house has a funky drain connection at the basement floor where I suspect we'll find the leak. Your buddy needs to stay outside while you are smelling around since he will have peppermint odor on his clothes and can "blow" the test by bringing the odor into the house. Also, don't open the peppermint oil on your way to the job...you'll destroy your nasal night vision..so to speak.
I'll let you know how we fare.