How to Replace a Leaking Air Duct

What You'll Need
Metal cutters
Duct compound
Sealing tape
Metal straps
New ductwork

Utility bills can be quite high and if you have air ducts that are leaking the electricity expenses on your home can rise even more. Leaking air ducts not only can it cost more to heat or cool your home but it also could be a hazard to your health. The ducts may create a build up of dust, or if it is even a little damp could cause mold. Second, when an air duct if they leaked carbon monoxide which is very dangerous to your health. In order to stop these leaks the following is a simple guide to help you repair the leaks in your air ducts by replacing the leaking air duct.

Step 1 - Inspect the Air Ducts for Kinks

Inspect all of the ducts in your basement, garage (if it has any) crawlspace or attic and see if any of these areas have ducts that look like they have a kink in them. The kink will cause leaking air.

Another area to look at would be where the heating and cooling joints meet, then split. Look at the tape that is on these joints and make sure if there are no cracks in them. There also could be lint or dust that has collected around these areas.

Step 2 - Check for Dirt and Grime

If the ducts are insulated you can tell if they have leaks as they likely will have a build up of dirt around the seals.

Step 3 - Turn Air Off and Install Metal Straps

Turn the air flow off to your home. Shut off the air conditioner and the heater.

You might find ducts that have started to droop and you can make these stronger by installing metal straps to the duct. These straps can be found at your local home improvement store. The strapping will bend easily around the duct and can be attached to the wood joists in the ceiling or wall. 

Step 4 - Remove Old Duct

Using a metal cutter, cut through the duct that has a leak and pull it off. Join a new piece of duct in the open spot. Seal the two pieces of ducts together with duct sealing tape and duct sealing compound. Once you have wrapped the sealing tape around the ducts you should use a compound of thick paste to help secure the tape. This compound is usually found in tubes which are easy to spread.

This type of compound also can be applied to the corners of the duct work to prevent any future leaking problems.

Step 5 - Turn Air Back On

Turn the air back onto your home and inspect the duct work. Apply a little water to the areas you have just repaired. If bubbles occur in those areas or locations then you still have a leaking air duct problem. If there is no sign of bubbles, then you have fixed the problem.