I'm replacing an existing bathroom fan and wanted to get some advice about the type of ducting to use. I would like to use insulated flexible ducting to reduce the possibility of condensation and also to help absorb some of the fan noise.
I was considering this ducting material: http://www.rewci.com/4infldu25.html
However, I believe that the California building code requires METAL ducting to be used for fire-prevention reasons. The web site that sells the ducting material says the insulated flexible ducting is certified by the City of Los Angeles and California Bureau of Home Furnishings (I live in Los Angeles county, but not in the city). How can I (easily) confirm that this material will meet my local building codes for this application?