Sealant Or Tape- Which Is Best To Repair Your Air Ducts?

The efficiency of your air conditioning system depends on the quality of your air ducts. Ducts can develop leaks over time, allowing cool air to spill out of the ducts before it reaches the living spaces within your home. These leaks require your air conditioner to work harder to cool your home, which can increase your cooling costs and result in premature system failure.

Sealing your air ducts regularly can be a simple and effective way to eliminate air leaks- and the problems they bring.

Mastic Sealant

There are two primary options when it comes to repairing leaky air ducts. You can use mastic sealant or tape. Mastic sealants are the option of choice for most professional contractors because they tend to last much longer than tape repairs.

The sealant itself comes in a pot and has a gooey consistency. A mastic sealant can be applied with a paintbrush over leaks in your air ducts. Larger areas that have sustained damage may require you to pair fiberglass tape with mastic sealant to achieve an airtight seal.

If you do need to use fiberglass tape to create a stable structure on which to apply a mastic sealant, be sure that you select the tape that matches your specific sealant tape to maximize your results.


If you don't want to deal with the mess of mastic sealant, your other option for repairing leaky air ducts is HVAC tape. Homeowners can confuse HVAC tape for duct tape, but the two products differ. HVAC tape is made to withstand the temperature fluctuations that exist within residential air ducts.

Look for butyl tape, foil tape, or another heat-approved tape when making duct repairs. Be sure that you take the time to thoroughly clean the area where you will be applying the HVAC tape. Taped repairs are more likely to fail if the surface they are adhered to is oily or dusty.

You will also need to check the repaired area regularly for delamination, as HVAC tape is susceptible to peeling over time.

Keeping your air ducts in good condition is critical when it comes to the performance of your air conditioning system. Air leaks can leave your home feeling less-than-comfortable, so invest in repairs to eliminate duct leaks as quickly as possible.

Weigh the pros and cons of both mastic sealants and HVAC tape products, then choose the repair method that is best suited to meet your needs in the future. Contact a service, like Allied Mechanical & Electrical, Inc., for more help.