How To Install Flex Duct In Attic

Isley s home service inc.

How to install flex duct in attic.

In this video i use mastic and air duct sealant t. I ll show you how to get the job done right. The supports need to be at the manufacturer s recommended spacing but no longer than 4 maximum. To prevent problems use saddles or straps to support at regular intervals 4c 4d follow the manufacturer s instructions but in case they get lost here is a list of best practices for.

The first thing you want to do is take either air duct sealant or mastic and spread it around the take off. Sometimes the best route for a flexible duct run is up and over an obstruction. Pull both sides of your ductwork so that the insulation is free of the ends and then wrap duct tape around both pieces. Slide the webbing under the flex duct.

Mastic comes in a bucket air duct sealant comes in a tube they re basically the same thing. Pull the webbing back toward the joist to form a loop. Continue throughout the line until air can be discharged at the exit. Another biggie that i see all the time is sagging ducts.

Pull down the insulation so that it covers the core. But without proper support ducts can develops sags or kinks that reduce airflow 4a 4b. Spread it around with either your fingers or a disposable chip brush or disposable paint brush. This is a short training video to show technicians and homeowners how to properly install flex duct to plenums.

The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports. Installing flexible or insulated duct is an easy diy project.