How to Save & Seal Ducts

Air ducts deliver conditioned air from the air handler to the house.

If you have old air ducts that are leaking you can patch and save them. A leaking air duct is a serious problem as it will cause air loss and increase energy use in a home. In most cases, the leaks will be in the joints between two sections of air ducts, which can be fixed. If you follow the proper directions and use the right supplies you can quickly save and seal your leaking air duct.

Things You'll Need

• Aluminum foil tape
• Mastic sealant
• Paint brush

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Instructions

1. Locate the leaking air ducts. Feel around the joints of the air ducts to see if you feel any air escaping the joints. If you do, then you have a leak. In most cases, you will have to climb into your attic or look at your basement to reach the air ducts. Once you have located the leaking joints, turn off the air conditioner.

2. Brush clean the surface of the air duct joint that is leaking. Brush off any dust and debris on the air duct.

3. Wrap the joint of the air duct with the aluminum foil tape. Ensure the tape overlaps at least 2 inches to both sides of the joint.

4. Paint a layer of mastic sealant over the aluminum foil tape. Dip the brush into the mastic sealant container and spread a thick layer over the tape and the joint.

5. Turn on the air conditioner and recheck for leaks. If you noticed more leaks in the joint, wrap another layer of aluminum foil tape and reseal it with mastic sealant.

References

• Energy Star: Duct Sealing