View Full Version : Bathroom Vent Leaving Building

12-10-2006, 01:34 PM
Hello All,

I have a building where there is a bad moisture problem. There is mold/mildew that grows on the ceilings/windows in the winter time. There are two causes for this; 1. Wet Basement (foundation may need to be excavated, and/or interior footer drains installed), and 2. No vent in the bathrooms. I had a plumbing/heating company give me an estimate to install bathroom vents. It is a ranch home with a very small attic space. The guy gave told me he would run the vents out so that they came out of the bottom of the soffit.

Question: Will running the vents out of the bottom of the soffit cause the moisture to over time soften and rot the soffit out? Would it be a better idea to run the vent out the roof?


12-10-2006, 06:49 PM
I know my bathroom is vented this way. I think I have even seen it as an option on exhaust fan boxes. Seems like it's fine as long as your soffit is not blocked up with insulation etc.

12-11-2006, 04:31 PM
Do it right, either run it out the roof, or the sidewall. Running it into the soffit is a hack - you want the moisture out of the house, not stuck anywhere in it.