In addition to new construction and remodeling, our company offers home energy assessments and any related energy-performance upgrades that may be needed. So we spend lots of time in attics fixing air-sealing and insulation problems, as well as addressing issues with bathroom fans. We often find that fans are vented directly into the attic area, or that the ductwork is poorly installed.
When hot, moist air is dumped into a vented attic in the winter, the water vapor generally condenses on the roof sheathing, starts mold growth, and eventually leads to structural damage. We also find that even when bathroom fans are exhausted to the outside, they're usually vented with flex duct, which is very restrictive to airflow.
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