We have two bathrooms side by side on our second floor. They both have the same exact layout (about 6'x7'). Both have their own separate exhaust fans (Nutone, 80CFM, 1.6amps), but share the same vent to the roof through a Y-shaped connector and flex 4" pipe. When we take steamy showers in bathroom A, paint from the ceiling of bathroom B is showing signs of moisture and paint is peeling in one area of the ceiling. We even noticed some condensation on the tile wall of bathroom B.
What could be causing the problem in bathroom B and how can we fix it?
Best Answer
If both fans are venting out the same exhaust port, i would check you have back-draft Dampers (one on each section before the presumed Y connector).
Its possible your first extractor is just blowing the damp air into the second bathroom - a damper should add enough resistance to the flow of air to make the damp air "prefer" exiting via the exhaust port rather than going through the second damper (and in to the second bathroom, causing the damp), without restricting airflow noticeably.