Winter + Bathroom Skylight + No Ventilation = Mold Problem

1/7/2020 (Permalink)

In the wintertime, the combination of cold air outside and warm, moist air inside this bathroom caused mold to grow around the skylight.

One of our Production Managers inspected a New Haven County home in which mold repeatedly grew around the skylight in the bathroom, despite the owner's efforts to remove it. 

The homeowner had expressed surprise that the mold was growing in the wintertime. Many of us might have the same reaction- as there is a misconception that mold is more prevalent in the summertime. However, mold growth occurs in the winter due to the amount of melting snow and ice combined with the warm temperatures inside of a heated home. Although heated homes do tend to make the indoor air drier, places such as the bathroom, especially one with a lack of ventilation, experience increased moisture. Warm condensation collected daily on the cold, snow covered skylight in this case and the mold had an ideal breeding ground.

The first step in a mold remediation job for us is always to identify and correct the source of the mold. At this home, the problem was clearly a lack of ventilation combined with a skylight in the bathroom. The owner was not in a position to remove the skylight nor did they have any control over the weather outside. However, a high quality exhaust fan could be installed to help remove the warm moist air out of the bathroom. By taking this measure, the moist air was circulated out of the bathroom and the mold no longer grew. The affected area was cleaned and damaged wood replaced and the air filtered until the mold spore count was at normal levels. All in all, it was a relatively easy and inexpensive solution which took care of the mold problem.