How To Install Flexible Duct In Attic

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.

How to install flexible duct in attic.

Continue throughout the line until air can be discharged at the exit. The first thing you want to do is take either air duct sealant or mastic and spread it around the take off. The straps that hold up the flex duct need to be no less than 1 5. But without proper support ducts can develops sags or kinks that reduce airflow 4a 4b.

The supports need to be at the manufacturer s recommended spacing but no longer than 4 maximum. Spread a thin layer of mastic glue onto the beaded end of the plenum or metal collar. Secure the webbing to the joist by hammering a 2 inch roofing nail through the webbing and into the side of the joist. Another biggie that i see all the time is sagging ducts.

Sometimes the best route for a flexible duct run is up and over an obstruction. Pull down the insulation so that it covers the core. How to hang flex duct in an attic 1. Attach the joint into the middle and secure with more duct work.

Hold the loose end of a roll of duct support webbing against the side of a roof joist sitting directly above the flex. The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports. Slip the flex duct s inner core over the plenum or collar and onto the mastic glue. Push the core so that it.

I use the caulking gun with air duct sealant to get back in the spaces it s hard to reach with the mastic. Pull both sides of your ductwork so that the insulation is free of the ends and then wrap duct tape around both pieces.