​ 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.

​Ice Dams:  Causes and Prevention
Winter is here again and while it has been fairly mild over all in Calgary, we have had a few periods of cold and snow as well. In December alone we had over 32 cm snow and some very cold temperatures. Our December snowfall combined with the warmer temperatures in January provided the perfect weather for ice dams to form. Sometimes ice dams can melt with warmer temperatures without causing any visible damage to the home.  Before we go into practical ways to stop ice dams, let’s take a quick look at what causes them, and the essential steps that must be taken to mitigate the problem.
Ice Dams happen when you have snow on the roof and the heat that escapes from inside your house / attic melts the snow. As snow melts, water runs down the roof, and when it gets to the roof edge (eaves) which are unheated, it once again freezes. As more and more water freezes along roof eaves, the ice builds up, creating ice dams. When even more water runs down, it now has nowhere to go, so it backs up under the shingles, and leaks into your roof.​