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Bathroom Exhaust Fan Duct Terminations

By
Home Inspector with Aldrich's Home Inspections, Inc.

On several recent inspections, I have noted bathroom exhaust fan ducts that are improperly terminated either inside the attic space or into an enclosed soffit. This is a concern because vents terminated near a roof ventilator, gable, vent, or eave vent or bird blocking might lead to reduced attic ventilation, impaired fan ducting, high humidity levels, decay and/or mildew-like staining. Below are a couple examples of my recent findings. 

This bathroom exhaust fan duct was terminated inside an enclosed soffit. This house had never been lived in so there was no visible damage... yet. 

Example of a bathroom exhaust fan duct terminated inside an enclosed soffit.

Below are three other examples of missing or incorrectly terminated bathroom exhaust fan ducts.

Examples of missing or incorrectly terminated bathroom exhaust fan ducts.

Below are some examples of the damage an improperly terminated bathroom exhaust fan duct can cause.

Examples of the damage an improperly terminated bathroom exhaust fan duct can cause.

Current standards call for all exhaust fan ducts to be completely vented to the exterior in a dedicated and proper roof vent and for good reason.

Gary Coles (International Referrals)
Venture Realty International - Las Vegas, NV
Latin America Real Estate

Jason,  This is interesting.  I recently saw a two-story home with the vent from the first floor bath (a 1/2 bath) terminated by going out through the wall to the outside.  It has a wall cap.  Is that considered ok? 

Thanks, Gary

Sep 14, 2009 05:18 PM
Jason Aldrich
Aldrich's Home Inspections, Inc. - Sequim, WA
Sequim, WA Home Inspector

Yes, Gary. I would consider the termination you describe as proper.

Sep 15, 2009 02:24 AM
Charles Buell
Charles Buell Inspections Inc. - Seattle, WA
Seattle Home Inspector

Jason, nice pictures-----good examples of the many ways venting gets done wrong.

Sep 16, 2009 12:18 PM
Steven L. Smith
King of the House Home Inspection, Inc. - Bellingham, WA
Bellingham WA Home Inspector

Jason,

I like those lower three best. In this field we see that sort of thing so often. People would not terminate them that way if they only knew.

Sep 17, 2009 03:54 PM
Erby Crofutt
B4 U Close Home Inspections&Radon Testing (www.b4uclose.com) - Lexington, KY
The Central Kentucky Home Inspector, Lexington KY

But, But, But, the pipe is stuck down into the soffit.  That's OK, isn't it.

No, Not really!

 

Go figure!

 

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Sep 23, 2009 01:31 AM