How to Replace an Air Duct System

Inspect all of the ducts in your home thoroughly to see if any of the ducts have leaks or breakage. A hole or crack can cause leaking air, so hold your hand up to the duct to feel if any air hits your hand. Also check where the duct joints meet and then split. Inspect the tape on these joints to ensure there are no abrasions.

Pinpoint the exact area that needs to be replaced. For small leaks, there is no reason to replace the entire air duct system. If the ducts are insulated, you should be able to tell if they have leaks as they might have a buildup of grime around the joint seals. Gather the new duct work that will be used to fix the faulty duct pieces.

Turn the air flow to your home off by shutting down the air conditioning or heating system. This process tends to be different with each particular air duct system. You might find some ducts have started to droop once the break has been discovered. They can be fixed by installing stronger metal straps to the duct. Metal straps can be found at a local home improvement store. The strapping is flexible and can bend easily around the duct work and may be attached to nearby wood joists.

Use a metal cutter tool to clip through the faulty air duct and pull it off. Join a new piece of duct in the open slot. Using duct sealing tape and sealing compound, seal the two pieces of duct work together. Once the sealing tape is wrapped around the ducts, use a compound of thick paste to help secure the tape in place. This type of compound can also be placed on the corners of the duct work to prevent future leaking. Allow a few minutes for the compound to dry.

Turn the air system back on in your home. Inspect the newly replaced duct to make sure it is properly sealed by using your hand to feel for air. Apply some water to the areas where the compound was used to make sure everything has sealed together. If bubbles pop up in those locations, there is still a problem with the air duct system. If there are no cracks or abrasions, then the air duct has been fixed. Place the insulation back over the duct system.