Check Sewer Vents for Ice Accumulations

George Maher, Farm Safety Specialist

If areas of your home are beginning to smell like a sewer, it may be your house's way of telling you some of its vital systems aren't working properly, says a North Dakota State University safety specialist.

"Toxic gases and fumes can present a serious hazard when sewer vents become plugged with ice," notes George Maher of the NDSU Extension Service. "The smell of sewer gas in the home is often the first indication of a problem."

Maher notes that heavy build-ups of sewer gas can be explosive. That pungent odor is offensive and usually quite noticeable.

Basement floor drains that have dried up will allow sewer gas to enter the home. These drains need to be checked and refilled with water. Pour a quart or two of water in these drains every week or so to keep them filled, Maher says. Adding a tablespoon or two of vegetable oil or mineral oil to the water in the drain will slow down the evaporation of the water in the drain trap.

If sinks, bathtubs and other plumbing fixtures don't drain normally, it may be another indication of ice build-up in the sewer vent.

Vents for the sewer system are located on the roof, usually above the rooms/facilities they serve. These vents, usually 2- to 3-inch diameter pipes, can freeze shut.

"Clearing a frozen sewer vent on the roof calls for extreme care," Maher notes. "The job usually involves a ladder and a slippery roof."

One remedy for sewer vents that repeatedly freeze up is to insulate the vent pipe where it passes through the attic, he says. Some fiberglass insulation wrapped around the pipe will probably do the job.

Another remedy is to install a newer style of sewer vent that resists freeze-up, Maher says. These vents should be available from hardware stores and lumberyards.