Featuring America's Home Inspector: Nationally Syndicated Columnist, Barry Stone

Crazy Buzzing In Bathroom Wall

The House Detective: by Barry Stone, Certified Home Inspector

Dear Barry:   I have an intermittent buzzing sound in my bathroom wall, and it’s driving me crazy. It only buzzes between sunset and 11pm every evening and is very noisy. I have tried turning off the electrical power at the main, turning off individual circuit breakers, and shutting off the water main, but the noise continues each evening. Sometimes it stops for five or ten seconds and then starts up again. A contractor suggested opening the wall to see what’s going on, but we just remodeled the bathroom, and we hate to tear things up. What do you advise?  Paul

Dear Paul:    Now that you have eliminated electrical and plumbing conditions as possible causes, the most likely suspect is a bee hive or wasp nest. Bees usually return to their hive around sunset, which is when you begin to hear the buzzing in your wall, and later in the evening they usually settle down for the night. Check your phone directory or the internet for local companies that specialize in bee hive removal. Unfortunately, you may have to cut open the wall of your newly remodeled bathroom.


Where to Properly Place Carbon Monoxide Alarms

The House Detective: by Barry Stone, Certified Home Inspector

Dear Barry:  I keep hearing conflicting opinions about whether to install carbon monoxide alarms high or low. Some people say that CO is heavier than air and is more likely to set off an alarm near the floor. Others say it is lighter than air and advise installing alarms near the ceiling. What is the truth about this, and what is the best place to install a carbon monoxide alarm?  Jamie

Dear Jamie:  This question comes up frequently in the course of home inspections, and incorrect information about carbon monoxide has become commonplace. So here are the facts. At standard temperature and pressure, the weight of air is 0.0807 pounds per cubic foot, and the weight of carbon monoxide is 0.0780 pounds per cubic foot. Considering the positions of the decimal points in these numbers, these differences are miniscule, making the relative weights of air and carbon monoxide nearly equal, with carbon monoxide being very slightly lighter. So what’s the best position for alarms, high or low?

To answer this question, an experiment was conducted in May of 2011 at the Center for Hyperbaric Medicine at Virginia Mason Medical Center in Seattle, Washington. The purpose of the test was to observe the way that carbon monoxide mixes with air and thus to determine the safest placement for carbon monoxide alarms, to provide the earliest possible warning of CO contamination in a home.

An eight-foot-tall Plexiglas chamber was constructed and three carbon monoxide alarms were installed, one in the top portion, one at the bottom, and one in the middle section. Carbon monoxide was then injected into the chamber in a series of tests. Sometimes, the CO was injected at the top, sometimes at the bottom, and sometimes in the middle. In each case, the CO diffused so rapidly with the air that there was found to be no apparent advantage in placing a CO alarm high or low inside a home.

What matters when installing CO alarms is to place them close to all bedroom entrances and to have one on each level of a multi-level home. Although not required, it is also advisable to install a CO alarm in the garage, since an idling vehicle is a likely source of carbon monoxide. And be sure to test each alarm regularly to make sure it remains operable.