Where should I vent my bathroom exhaust fan?

Bathroom exhaust fans must be vented directly to the exterior of your home - never into an attic, crawl space, or other interior area. This prevents moisture buildup that can cause mold, rot, and structural damage.

The best venting locations are through the roof or an exterior wall. Roof venting is often preferred as it provides the shortest duct run and natural updraft, but requires proper flashing and weatherproofing. Wall venting works well for upper floors and is easier to seal, but may be more visible from the exterior.

In Ottawa's climate, proper venting is critical due to our cold winters and humid summers. The duct should be insulated to prevent condensation and include a backdraft damper to stop cold air infiltration. Use rigid metal ducting when possible - flexible ducts can sag and collect moisture. The exterior termination should have a weather hood and be positioned away from windows, doors, and air intake vents.

Ontario Building Code requirements specify that bathroom fans must exhaust directly outdoors with proper dampers and weatherproofing. The duct should be as short and straight as possible, with minimal bends that reduce airflow efficiency. For basement bathrooms, you may need to run ducting through multiple floors to reach an exterior wall or roof.

Professional installation ensures proper sizing, code compliance, and weatherproofing. Improper venting is one of the most common causes of bathroom moisture problems in Ottawa homes. For complex routing or roof penetrations, consider consulting with Ottawa Bathrooms for proper installation that protects your home's structure.