How to Install Flexible Duct
Installation Tips & Tricks — To cut flexible duct, use a steak knife from your kitchen drawer to cut through the outside jacket, fiberglass insulation and inner plastic core. Then cut the wire with a pair of wire cutters. To attach flexible duct to a sheet metal fitting, fold back outer jacket and fiberglass insulation. Insert sheet metal fitting into the inner core and fasten securely with duct tape. Fold fiberglass insulation and outer jacket back over the sheet metal fitting and secure with Zip Ties then pull insulation jacket back over duct fitting and wrap with duct tape.