How to Perform Air Duct Repair Yourself

fixing air duct with tape
  • 2-3 hours
  • Intermediate
  • 50-200
What You'll Need
Mastic sealant
Duct tape
Paint brush
Panduit strips
Fabric mesh
Caulk mastic
Caulk gun
Foil tape
Putty knife

If you suddenly realize that your heating and cooling costs are beginning to be unusually high, that could mean that you are in need of air duct repair. The main thing that generally causes this is a hole in the air duct that allows for a loss of energy. In order to save yourself some money, check to see if there is easy access to ducts. If there is, then you can fix this problem yourself without calling in a professional to do the work. Follow the guide below to do just that.

Step 1 - Find the Holes

Check to see where the hole or holes might be located. You can do this by turning your thermostat to 'On' and not 'Auto.' Once you have done this you can examine the ducts in order to find where they are leaking. After you have found the leak turn off the thermostat.

Step 2 - Fix the Flex Duct

If you find that the flex duct is loose and has fallen off, you will need to remove the previous Panduit strip. Now pull the outer layer and insulation back about 8 to 12 inches and fit the inner layer into what is called the boot connection. Secure it with duct tape and secure inner layer with a new Panduit strip. Put the outer layer back on and secure with another new Panduit strip.

Step 3 - Fix a Rip

Should the flex be ripped, the first thing you should do is to clean the ripped flex very good so that there is no problem with creating a seal. Hold the ripped part together and secure them with some duct tape. After you have done that you will take some of the mesh you have and place it on the rib. Then you will take the paint brush and paint the mastic sealant over the mesh. Put plenty on the area. Allow it to dry for at least 10 minutes. If you find that the rip will not hold, try stapling it together.

Step 4 - Test the Duct

You should wait a few minutes after the sealant has dried before you test the duct. Once you are ready to test it turn the thermostat back on. If you feel no air coming through where the mend is, you have fixed your problem.

Step 5 - Seal the Heat Duct

Sealing a heat duct is a little different since you will need to use caulk and a caulking gun. Where you find the leak you will use the caulk to seal up the area that is leaking. Using a putty knife you will cover all the seams and joints that need to be sealed. When you can’t reach a certain area you should try to use foil tape and acrylic adhesive. This will hold better than duct tape. Make sure to check the caulking tube to see how long it takes to dry before turning the unit back on.

    Of course if none of this works you may have to actually replace the ducting. Either way, doing it yourself will save you a ton of money.