Help Support the Allowable Use of Flexible Duct for Final Connections to Air Outlets


IAPMO is considering a clarification to the UMC this week that, if approved, would immediately clarify that flexible duct shall be permitted for use as an elbow at a terminal device. They need to hear your support for this proposal before Friday, July 28th.

ISSUE: The UMC changes that became effective in CA on January 1, 2017 are being misinterpreted by some local building officials as a ban on the use of flexible duct for elbows on final connections to air outlets. This was never intended to be the case. SMACNA and Local 104 have jointly submitted a Temporary Interim Amendment (TIA) to IAPMO for formal approval to make it clear in UMC 603.4.1 that “flexible duct shall be permitted to be used as an elbow at a terminal device.”

We need your support for this proposal today

Take action now:

Step 1: Please print out this document

STEP 2: Complete the FORM FOR TIA COMMENT ON IAPMO UPC/UMC COMMITTEE DOCUMENT on page 2. Make sure to check the box that you “AGREE” with the TIA. Also include substantiation for your comment in the space provided.

A sample substantiation is:

“There is significant confusion in the field leading to unnecessary costs and penalties to contractors and building owners. [INSERT ANY EXAMPLES OF LOCAL ENFORCEMENT ISSUES IN YOUR AREA] This proposed clarification will provide structure to the industry and reduce the cost burden now impacting all parties.”

STEP 3: Scan the completed form and email to; or FAX to Enrique Gonzalez at (909) 472-4246. If you should have any questions on submittal of your comments you may reach Enrique at the IAPMO offices at (909) 230-5535.

STEP 4: Send a copy of your comments to or FAX to (916) 363-7544

Remember: Deadline to submit is Friday, July 28th!