Exhaust Fan Duct Material

   **  I have a fellow inspector that frequently uses the comment: **

· The plastic materials used for the mechanical exhaust vent flues are not listed or labeled for use in enclosed attic areas. This is an “as-built” condition but Per TREC standards of practice we are required to report this condition as a deficiency.
Since I cannot find any information in the IRC or TREC Standards of Practice, I question the validity of this statement. Please let me know where I can find any backup information to verify this statement.
Thank You,

                                                                     Bud Robertson

Save yourself the trouble, simply ask your fellow inspector the question ;-).

That reply did not help much. I assure you I first did ask that question. I did not get a good answer. I decided to reach out to my fellow Internachi inspectors.

Bud…if the duct material is listed as UL181 compliant then it is acceptable. That’s the simple answer. Now, I’m assuming you are referring to a bath exhaust fan duct like this. See 2006 IRC M1506.1 & M1601.2.