How To Install Flexible Duct In Attic

The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports.

How to install flexible duct in attic.

The first thing you want to do is take either air duct sealant or mastic and spread it around the take off. Continue throughout the line until air can be discharged at the exit. Hold the loose end of a roll of duct support webbing against the side of a roof joist sitting directly above the flex. How to insulate your attic duct system step by step with video instructions as winter nears many will begin to activate their home heating system to keep the house warm in the blustery and frigid temperatures that accompany the change in seasons.

But without proper support ducts can develops sags or kinks that reduce airflow 4a 4b. Slip the flex duct s inner core over the plenum or collar and onto the mastic glue. Spread a thin layer of mastic glue onto the beaded end of the plenum or metal collar. 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. Another biggie that i see all the time is sagging ducts. The straps that hold up the flex duct need to be no less than 1 5. Attach the joint into the middle and secure with more duct work.

How to hang flex duct in an attic 1. I use the caulking gun with air duct sealant to get back in the spaces it s hard to reach with the mastic. Ensuring your attic is properly insulated is essential to this endeavor. Push the core so that it.

Pull down the insulation so that it covers the core. Sometimes the best route for a flexible duct run is up and over an obstruction.