Venting bathroom fans

About 40 percent of the inspections I undertake have a problem with the venting systems of the home. Some problems are minor such as a vent hood that has been damaged or the flap is stuck open. The more severe problems would include mold growth and stains on the ceilings or moisture in walls. With our wide ranging weather patterns it is crucial to move stale moist air from your home effectively. Usually the home owner has no idea that there is a problem until someone gets sick or they begin to see physical evidence of the problems.

The most common issue with poor venting is excessively high moisture levels inside the home or attic that eventually creates stains or mold. With ceiling exhaust fans the problem is usually one of three things, un-insulated vent lines in the cold attic that condenses and leaks , water traps that slow down or stop air flow and vent lines that terminate inside the attic. The end result of all of these issues is usually high humidity and moisture related stains and mold growth.

Failure to vent the moisture and stale air out of the home tends to show up as condensation and mildew on the window sills and even mold under the windows on the drywall. Most people realize that the moisture levels are high and turn on the fans only to find it doesn’t get any better. The problem is usually improper venting that actually is not moving any air.  Many times the builder tries to avoid moisture in the ceiling fan by creating a water trap in the vent line. More often than not this water trap turns into a block of ice and shuts down the ability of the fan to move air. Another common problem is un-insulated fans and vent lines which tend to frost up. The solution is quite easy, buy insulated vent line and vent the fans up and out through the roof without any low spots. Secondly make sure the fan is covered over with adequate amount of insulation and poly if possible. There is a lot more that can be said on this topic so feel free to call or visit our website for more information.