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Bathroom moisture during summer is often less concerning when windows are open throughout the home. For closed baths or during winter months, a bathroom exhaust fan removes moisture condensation preventing moisture and mold damage to walls, vanities, and other surfaces in your bathroom. A bath fan also helps to circulate fresh air in your bathroom keeping it smelling fresh.

As more and more homes today have dedicated laundry rooms on the first and frequently on the second floor (rather than the basement), homeowners are using bath exhaust fans to also prevent moisture, mold, and mildew problems in their laundry room as well.


Well, that really depends. Most homeowners believe their bath fans and dryer ducts exhaust to the outside. But that is often not the case. Far too often we find them exhausting up into the attic. And that is not good. Basically, you are taking moisture from your bath or laundry rooms and dumping it into your attic which can lead to even bigger problems.


When bath fans exhaust or dryers exhaust into the attic, the moisture is released into the attic where it can do significant damage. The only way to know is to go up into the attic and identify each exhaust fan location. If you don’t see a duct connected to the roof or soffit, your fan is dumping into your attic space.


Ongoing moisture can build up on surfaces in the attic. This will lead to wood deterioration including all exposed wooden support structures and the sheathing supporting your roof tiles.  Over time, this will lead to premature aging and damage to your roof.

If you store personal items in the attic any cardboard, paper, and cloth items can be destroyed. Moisture will often lead to mildew and mold. If mold develops and is left unaddressed, mold colonies will expand rapidly throughout the entire attic. At that point, mold mitigation is required. Left unaddressed, mold can spread to living spaces below. If you see tiny gray spots in where your walls meet the ceiling, you may have a mold problem in your attic. It won’t go away on its own.

Lastly, moisture can damage insulation. Wet insulation does not properly insulate. When insulation is not working properly, heating and cooling systems must run longer to achieve living areas, increasing utility costs until the wet insulation is replaced. And of course, this has a negative impact on your monthly utility bills.


Moisture is often evident in winter or spring when surfaces are wet to the touch. Other signs of moisture include dark stains on wood surfaces, evidence of mold growth. If the wood is soft and flaking, it is already deteriorating from the moisture. At this stage, repairs are necessary.

If you don’t see problems but discover your bath fans, dryer exhaust or both are exhausting in your attic, have the exhaust re-routed outside.


Properly installed exhaust should be connected to an insulated duct that routes the moisture outside. This is an affordable improvement that can save you thousands of dollars worth of damage in the future.


We carry a variety of bathroom exhaust fans and provide full installation including proper exhaust for both bath fans and dry exhaust.

Call Attic Air for a Free Attic Assessment today! 630-830-3870