Mold In Attic From Bathroom Fan

Telltale black mold stains typically result from this ventilation error.

Mold in attic from bathroom fan. 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. During cold weather warm moist air blown into a cooler attic will deposit its moisture on attic rafters and roof sheathing. When warm air rises in your home it escapes through the attic leaving a vacuum behind.

It is important to have a balanced ventilation system using equal amounts incoming and outgoing air. The vacuum is then covered by air from the basement and crawl space that contains impurities like dust mites mold spores and odors. 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. Dryer vents plumbing vents kitchen or bathroom fans vented into the attic.

Moisture food and warmth. Http youtu be pne imqvfoy it shows the things we noticed to diagnose the bathroom fans venting. Also plumbing stacks in the attic can be a source of condensation which can lead to attic mold growth. 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.

Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems. 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. 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. If you eliminate just one of these elements mold will starve and die.

This is a different perspective from the other video about bathroom fan venting causing mold. In many cases moisture from bathroom fans is the primary source of attic mold infestation. For bath fans it is important to insulate around the vent pipe exiting the fan to prevent moisture from condensing inside the pipe.