Carmen asked us the building codes in Ontario generally say about the proper location on a house (the roof or fascia/soffits) for venting bathroom fan air to the outside. Bathroom fan expert Glenn Curtis, Soler Palau Canada, has the answer.
July 11, 2014 by Steve Payne
Question from a reader, Carmen, about bathroom exhaust fan venting:
“I would like to know, when venting a bathroom exhaust fan should it be vented up through the roof? Getting different opinions. Some say yes, some say it should be vented through the fascia. I live in Ontario, so does snow on roof change things?”
Response from a bathroom fan expert, Glenn Curtis of Soler Palau Canada, a manufacturer of bathroom fans – among other products.
It is really a matter of choice as to where the bathroom fan is vented to the outside, as long as it exhausts directly outside. The good majority of bathroom fans are vented through the roof, while some people are choosing to soffit vent them as an alternate. There is no definitive answer in the codes that pertain to where the air must vent out of the house. One thing to keep in mind, though, if choosing to soffit vent the fans, especially in Ontario, is that you are exhausting warm, moist air from the bathroom. In the middle of winter, this can create a situation where the exhaust point may become frozen and create a blockage.”