At this time of year with the onset of cold weather and fluctuating temperatures, homes in the Calgary area can experience problems with bathroom fans that leak water or develop stains on the ceiling around the vent.
Properly installed and used a bathroom fan should not leak in the summer or in the winter. If the vent does not leak in the summer, especially during the heavy rain that often accompanies thunderstorms, it indicates that the shingles and flashings were installed correctly and shedding water off the roof as intended. Water that drips from the fan during cold winter weather is usually an indication of a problem with the venting system not the roof itself.
During cold weather some moisture will always condense on the inside of the vent pipe, where it passes through the cold attic.
To operate properly a bathroom fan venting system needs to move sufficient air up an insulated pipe and outside of the house to remove excessive moisture from the home. This requires a fan that is rated to move enough cubic feet of air for the size of the room being vented, a vent pipe large enough that this air flow is not restrict and a vent in the roof to allow air out of the home and keep water from leaking in.
Properly installed and used a bathroom fan should not leak in the summer or in the winter. If the vent does not leak in the summer, especially during the heavy rain that often accompanies thunderstorms, it indicates that the shingles and flashings were installed correctly and shedding water off the roof as intended. Water that drips from the fan during cold winter weather is usually an indication of a problem with the venting system not the roof itself.
During cold weather some moisture will always condense on the inside of the vent pipe, where it passes through the cold attic.
To operate properly a bathroom fan venting system needs to move sufficient air up an insulated pipe and outside of the house to remove excessive moisture from the home. This requires a fan that is rated to move enough cubic feet of air for the size of the room being vented, a vent pipe large enough that this air flow is not restrict and a vent in the roof to allow air out of the home and keep water from leaking in.