Watch the full : \r \r Richard Trethewey shows an innovative new way to seal ducts from the inside. (See below for steps.)\r \r Click here to SUBSCRIBE to the official This Old House YouTube channel: \r \r Watch new s of Ask TOH: \r \r Steps for How to Seal Leaky Ductwork:\r 1. Remove the grilles from all of the supply and return registers.\r 2. Plug each duct register with foam rubber and wide strips of tape.\r 3. Pressurize the duct system with a blower fan.\r 4. Use a computer to analyze the data to determine the amount of air leaking from the ducts.\r 5. Use the blower fan to mist the inside of all the dust with liquid-rubber sealant.\r 6. The sealant will find and plug all air-leaking holes, cracks, and seams.\r 7. After applying the sealant, run another pressurized blower test to verify the improved results.\r \r Follow This Old House and Ask This Old House: \r Facebook: \r Twitter: \r \r Pinterest: \r G+: \r Instagram: \r Tumblr:
