[quote=Duke M. Pham]
Thank you very much for all your advices and responds.
My sincere apology for a missing information: the flex ducts were installed under the subfloor (on the ceiling before covered up by sheetrock).
I don’t know about the “Reference Manufacture’s Installation Instructions” of this flex duct, but I have found and referred to the ADC Flex Ducts Performance & Installation Guidelines before I knew and joined this forum. I feel regret that I have not know this forum earlier. The inspector I’ve hired is a Texas License Inspector; however, I believed I’ve hired a wrong guy even though he also has P.E. license (construction P.E., not Mech P.E.). He told me that this flex ducts installation is “no problem”, and he said because of the thick jacket then the core won’t get “hurt” by the compression (?!?!).
Beside this matter,** I was back out of this house due to many other construction defects,** specially, foundation issue is one of them along with other customer service satisfactory matters. (quote)
The informed person is the one ahead of the game to many choices in homes available to just blindly purchase.
I have installed miles and miles of duct in my career and if someone had asked me to install flex duct within an concealed wall or floor cavity I would have declined the job.