Related to 3 above this practice can pump warm moist air into the attic where it can be trapped and begin the cycle of mold growth.
Mold in attic from bathroom fan.
Moisture and mold in the attic if your bathroom fan exhausts into your attic and not outside of your home you could start having serious issues with moisture and mold.
Surviving mold in your attic venting a bathroom fan into an attic my detailed home ventilation won t prevent attic mold growth healthy indoors home inspection finds bad bathroom fan venting le to moisture where does the bathroom fan take all air quora.
The vacuum is then covered by air from the basement and crawl space that contains impurities like dust mites mold spores and odors.
For bath fans it is important to insulate around the vent pipe exiting the fan to prevent moisture from condensing inside the pipe.
This is a different perspective from the other video about bathroom fan venting causing mold.
Moisture food and warmth.
Http youtu be pne imqvfoy it shows the things we noticed to diagnose the bathroom fans venting.
During cold weather warm moist air blown into a cooler attic will deposit its moisture on attic rafters and roof sheathing.
Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems.
So make absolutely sure that they terminate outside your home and never in the attic.
The spread of attic mold is through spores because it is light and easy to carry in the air.
Mold needs 3 things to grow.
Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons.
Also plumbing stacks in the attic can be a source of condensation which can lead to attic mold growth.
If you eliminate just one of these elements mold will starve and die.
When warm air rises in your home it escapes through the attic leaving a vacuum behind.
Dryer exhaust vents kitchen exhaust fans and bathroom exhaust fans are designed to pump moisture out of your home.
In many cases moisture from bathroom fans is the primary source of attic mold infestation.
Some builders mistakenly allow the fan to blow moist air into the attic a practice that simply moves the mold problem to another part of the house.