Before you add ANY plastic to your dryer, check with your local Building Department.
The following building code requirements are the current minimum code standards, as taken from the IRC Code & Commentary 2006, required for crawlspaces in One and Two family dwellings, and based on Kentucky Amendments to the 2007 Kentucky Residential Cod 2. Transition Duct Connectors. (IMC 504.6) specifically addresses transition duct connectors.
“Within the context of this section, a transition duct is a flexible connector used as a transition between the dryer outlet and the connection point to the exhaust duct system. Transition duct connectors must be listed and labeled as transition ducts for clothes dryer applications. Transition ducts are currently listed to comply with UL 2158A… Transition ducts are metalized (foil) fabric supported on a spiral wire frame.
They are more fire resistant than the typical plastic spiral duct. Transition duct connectors are limited to 8 feet in length and must be installed in compliance with their listing and the manufacturer’s instructions. “These duct connectors must not be concealed by any portion of the structure’s permanent finish materials such as drywall, plaster paneling, [e.g. flooring, ceiling, wall], built-in furniture or cabinets or any other similar permanently affixed building component; they must remain entirely within the room in which the appliance is installed (Section G2439.5, International Fuel Gas Code, Chapter 24, 2006 IRC).” http://www.hcpdc.com/pdf/Dryer%20Ven...quirements.pdf
Do any dryers use 3" ducts? I thought they all required 4", per IRC.
Be safe, Gary