A man checking his air ducts with the words, "how to patch an air duct leak."

If you’re an average homeowner wondering how to patch an air duct leak, the answer is that you don’t. Only a trained professional should take on this job because it requires inspecting a lot of equipment and a high level of familiarity and expertise. You might be curious about what steps a trained professional takes to resolve this issue, though. It’s understandable that you’d want to know more about what is needed to complete this job and how it might affect your home. Read on to learn more about how a trained professional patches an air duct leak.

1. Inspecting the Air Duct for Leaks

The first order of business is to check the air duct for leaks. After all, just as you can’t find a solution without first knowing the problem, you can’t fix the leak if you are not sure where or how many leaks are occurring.

Start by checking the main unit and its large ducts.

Identify the main unit and large ducts. These are connected to the branch ducts that run through the house. One side of the duct system blows air through the branch ducts, while the other side pulls air in.

Turn on the HVAC system and feel around all air duct connections for any air leaks.

Sometimes it is smart to wet the hand as this adds extra sensitivity to any passing air from a leak. Some professionals may use an incense stick or a thin piece of toilet paper instead. The moving smoke or toilet paper can be an indication of a leak.

Next, check the branch ducts.

The expert will check the areas in your home where the ducts are visible. Usually, that will be the basement or attic. They will also check the insulation surrounding the ducts for any damage. Such damage may include:

  • Torn pieces
  • Damp spots – wet areas could indicate that there is a blockage, which can negatively affect the indoor air quality. This section would need to be cleaned.
  • Mold – mold indicates that there is a moisture problem.

2. Patching the Air Ducts

Aluminum foil tape, or another heat approved tape, is often used to patch leaks on the flat surface where two pieces of metal are joined together. The expert will fully clean the area before applying the sealant. Once the area is thoroughly cleaned, a strip of sealant tape is placed over the leak. Alternatively, the expert may use a mastic sealant and a paintbrush, but the principle is the same. Mastic sealant is just easier to maneuver.

3. Potential Additional Steps

In order to prevent further issues and ensure that the only issue was a leak, an expert may check to ensure that the ductwork insulation has a proper vapor barrier to avoid mold and moisture problems. They may also test CO detectors to ensure they are working properly.

Ductwork Inspection, Installation, and Repair Specialists

There’s no need to worry if you’re not sure where to find a trained professional to handle patching an air duct leak. Our experts at Comfort Masters Heating & Air Conditioning have you (and your air ducts) covered. Whether it’s something as involved as an air duct leak or something as specific as diagnosing a noise coming from your air conditioning unit, Our team can make sure everything is in tip-top shape. Call us today!