Repair Large Holes Or Tears In Insulated Ductwork

Hvac Duct Repair Hole

3 DIY options to repair large holes or tears in your insulated flexible ductwork.

 

Zip Tie Damaged Ductwork Fix

This budget-friendly repair makes quick work of large hole or tear repairs in your ductwork, and works best if there is enough slack in the ductwork to allow losing a few inches in length.  If the ductwork is taut, you’ll need to use a connector to make up for the reduction in length after you’ve cut away the damage (if this is your situation – see the other repair options outlined below)

We apparently had some uninvited guests stay with us over the winter in our crawlspace, and they managed turn our ductwork into their own heated housing.

Hvac Duct Repair Hole

Hvac Duct Repair Hole

The ductwork had a lot of slack in it.  Even after cutting away 6 inches of damage, the ends of the flexible duct could easily be pulled together.  That meant we could fix it without needing a connector to span the lost section of duct.

Step 1

To start, we pulled back the insulation and cut off the damaged section of duct, and reinforced each of the ends of the duct with several layers of foil tape.

Hvac Duct Repair Ends Reinforced

Hvac Duct Repair Ends Reinforced with foil tape

Step 2

The ends were then secured together using five 6-inch zip cable ties with label tags.

Hvac Duct Repair Ends Tie Strap Connected

Hvac Duct Repair Ends Tie Strap Connected

The label portion of the zip cable ties made it a lot easier to close up the ends, especially when the duct was in a hard-to-reach area.

Hvac Duct Repair Ends Tie Strap Connection Closed

Hvac Duct Repair Ends Tie Strap Connection Closed

Step 3

The entire repaired area was covered and sealed using foil tape.

Hvac Duct Repair Ends Tie Strap Connection Taped

Hvac Duct Repair Ends Tie Strap Connection Taped

Step 4

The insulation was pulled back over the flexible duct repair and secured into position with more foil tape.

Hvac Duct Repair Ends Tie Strap Connection Sealed

Hvac Duct Repair Ends Tie Strap Connection Sealed

Products used:


Use Semi Rigid Aluminum Duct To Repair Ductwork

For damaged sections of ductwork where we had to remove longer sections of duct, we used semi-rigid aluminum duct and large cable ties to span the repair (product links below).

The semi-rigid aluminum duct came in an 8 foot section and was easily cut into the lengths we needed for each repair.  Because we had so many areas to repair, it was much cheaper to buy the semi-rigid than to buy individual duct connectors.  One 8 foot section of aluminum cost $15 and repaired 7 large holes.  If we had purchased 7 individual duct connectors at $5 each, it would have cost $35.

Hvac Duct Repair Semi Rigid

Hvac Duct Repair Semi Rigid

Although you can’t see it in the photo below, a 2 inch cut was made on each end of the semi-rigid aluminum duct so that it would crimp enough to slide into each of the exposed ductwork ends.

Hvac Duct Repair Semi Rigid Inserted

Hvac Duct Repair Semi Rigid Inserted

You will want to have the semi-rigid  inserted at least an extra 4 inches into each end of the ductwork.

Hvac Duct Repair Semi Rigid Inserted Two

Hvac Duct Repair Semi Rigid Inserted Two

Then slide each end of the original duct over the semi-rigid and secure into place using either zip cable ties or adjustable duct clamps.

Hvac Duct Repair Semi Rigid Inserted Tie Strap

Hvac Duct Repair Semi Rigid Inserted Tie Strap

Products Used:

Using Splice Collar Duct Connectors To Repair Damaged Duct

If you prefer to make repairs using the correct tools for the job, here are links to splice collars and metal hose clamps that are typically used to repair large holes or tears in ductwork.

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