ARAC Roof It Forward Case Studies: Is Your Bathroom Attic Vent Properly Venting?
Upon inspection for heavy freezing condensation in this attic, we noticed this bathroom vent not connected. It appears that the outside wall vent had lost its folding door assembly. This allowed birds to peck through the vinyl hose and enter the attic. As you can see around 6 inches of straw was brought into the attic in a 3'x3' area. Also discovered were bird dropping and one carcass of a dead bird. This not only did not allow the bath vent to exhaust warm moist air out of the attic but can cause a series health issue if not addressed properly. This disconnected hose can cause you some serious issues. The warm moist air that comes out of this vent will rise to the peak of your home. This can allow condensation and frost to appear on the underside of your roof decking. And as the weather warms this frost will melt and cause leaks to your ceiling as it falls.
The best solution here is to replace the exterior was vent with a new one have a retracting door damper. One the inside bag up the straw and all bird droppings and evidence of birds as well as the old insulation under the straw. Then install new insulation in the area affected. The hose should be a flexible aluminum hose, not a vinyl type hose. Connect the hose to the end of the damper vent and to the bath vent using hose clamps. It is always a good idea to inspect your attic at least once a year. Never know what you might find up there. This home was a beautiful and more than well-maintained property. All other areas of this attic were very tight and draft free.