More in Winter Upkeep

Freezing Vents

freezing vents

Our roof vent pipe sometimes gets blocked
by ice in the winter. When this happens, just one toilet flush will suck the traps dry and fill the house with a wicked septic-tank odor.
My husband then climbs on the roof with a kettle of hot water and pours it down the
pipe. This works perfectly, but it's rather inconvenient. Can you suggest an easier way?
—Elizabeth Gauthier, Vermilion Bay, Ontario, Canada


Richard Trethewey replies: Rather inconvenient? Anything that forces someone out on an icy roof is downright dangerous.

Although I'm not a big advocate of roof­top heating cables, this is one case in which they might be justified. You could wrap the ­cable around the vent-before winter comes- and plug it in whenever you think ice might be forming. Or you could get a ­cable that's ­ther­mostatically controlled. It might also help to cover the pipe with insulation, ­particularly where it passes through the attic.

The Canada Mortgage and Housing Corporation has this suggestion: Splice an ­upside-down­Y-cleanout into the vent stack just inside your attic. When the vent clogs at the roof, unscrew the cleanout's access plug and push a stiff wire up the pipe to open the clog. Then your kettle could be used for something better, like making hot chocolate.


TV Listings

Find TV Listing for This Old House and Ask This Old House in your area.