How To Install Flex Ductwork In Attic

Peel off part of the backing.

How to install flex ductwork in attic.

Spread it around with either your fingers or a disposable chip brush or disposable paint brush. If the ducts are going to be concealed all seams need to be taped or caulked. Another biggie that i see all the time is sagging ducts. Your support joints must be at least 4 inches long and be beaded both sides.

Here s bob s trick for taping a seam on a pipe that s installed close to the subfloor. Choose properly sized ducts. Slide the webbing under the flex duct. Add a support joint and then place another piece of the ductwork onto this.

But without proper support ducts can develops sags or kinks that reduce airflow 4a 4b. Secure all connections and seams air tight with heat resistant tape recommended by the duct manufacturer. 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. Attach the joint into the middle and secure with more duct work.

Give your ducts the proper support. One of the most common mistakes when installing attic ductwork is choosing. The supports need to be at the manufacturer s recommended spacing but no longer than 4 maximum. Mastic comes in a bucket air duct sealant comes in a tube they re basically the same thing.

How to properly install ductwork in an attic tip 1. Slide connectors inside the duct on each end. The first thing you want to do is take either air duct sealant or mastic and spread it around the take off. The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports.

Add extra insulation to ducts in areas such as attics where cold wind might blow in. Slide the backing up and over the pipe. Sometimes the best route for a flexible duct run is up and over an obstruction. Leave backing on the tape on metal ductwork.

Cut a piece of foil tape to length. This is an especially relevant tip for flex ducts more on that in a. The straps that hold up the flex duct need to be no less than 1 5. Pull both sides of your ductwork so that the insulation is free of the ends and then wrap duct tape around both pieces.