Why Duct Tape Should Never be Used on Ducts

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Why Duct Tape Should Never be Used on Ducts

Duct tape is incredibly strong and versatile. This material is a bit of a superstar in the DIY world, where its uses can range from mending broken appliances to curing warts. Despite what the name suggests, however, it should never be used on your air ducts. Read on to learn why you should avoid using duct tape for air duct repairs and what to do instead. 

Need professional ac service, Duncanville, TX neighbor? Give the team at Dial One Johnson Plumbing, Cooling and Heating a call at (972) 992-1495 or visit us online today.

Why Duct Tape and Air Ducts Don’t Mix

It may be tempting to seal air duct leaks, cracks or other forms of damage with duct tape, but there are several reasons why this isn’t the best solution. Let’s dive in.

Temperature Changes

Consistent exposure to heat and extreme temperature changes can break down the adhesive on duct tape over time, rendering it useless. Once the adhesive goes, duct tape can fall off entirely, or weaken enough to allow for air duct leaks — which is likely the problem it was meant to fix in the first place. 

Our air ducts are prone to temperature shifts, not only from the air conditioned or heated air constantly traveling through them, but from external factors as well. This includes instances where sections of air ducts run through uninsulated areas in the home, such as the attic, where extreme heat and cold conditions can wear down duct tape over time.  


As a result of constant temperature shifts, air ducts are also prone to forming condensation. This constant exposure to moisture will weaken duct tape, again causing it to fall off or or allow for air leaks. 

Air Duct Leaks

Aside from an inevitable decrease in performance, duct tape that is improperly placed or doesn’t form an airtight seal will still allow for air leaks. Air leaks occur when conditioned air from your HVAC unit escapes into unused spaces, like attics or basements. This makes it harder for your HVAC system to keep up with heating and cooling demand inside your living areas. 

Air duct leaks lead to decreased efficiency from your unit, increased wear and tear on your system and skyrocketing utility bills. Duct tape may seem like an easy fix, but the benefits will likely only be temporary. To ensure you’re getting the most out of your heating and cooling system, it’s worth investing in proper repairs. Anything less will end up costing you in the long run.   

The Right Way To Fix Your Air Ducts

There are effective alternatives to duct tape that homeowners can use to patch small holes and cracks, or to reinforce air duct joints. Let’s take a look:

Foil Tape 

Foil tape is an excellent alternative to duct tape. Owing to a specialized kind of adhesive, foil tape won’t dry out and lose effectiveness as a result of extreme temperature shifts. In addition to its adhesive, the aluminum backing on foil tape can also withstand significant temperature changes common in spaces like attics and basements. 

Duct Putty

Duct putty, a pliable substance sometimes referred to as “duct mastic,” can be used to seal duct joints, cracks and large holes. Homeowners will need to cover the target area with a fiberglass mesh tape before painting over it with duct putty.

Professional Air Duct Maintenance

Regular air duct maintenance from a professional HVAC company will help homeowners identify and prevent issues like air leaks before they can cause major headaches. Keeping air ducts clean will also help improve HVAC efficiency, increase indoor air quality and reduce the potential for hazardous issues like mold and mildew growth. 

When air ducts require extensive or frequent repairs, it may be more cost effective in the long run to consider installing new air ducts, or replacing the damaged section. A qualified HVAC technician can evaluate your system and recommend the best course of action to suit your needs and your budget. 

Homeowners can help keep their air ducts clean and efficient with the following HVAC maintenance tasks:

  • Replace or clean (if reusable) air filters every 30–90 days
  • Schedule professional HVAC tune-ups in the spring and fall to ensure the whole unit receives a thorough cleaning and inspection
  • Practice “source control” by dusting, vacuuming and grooming pets frequently to keep contaminants out of your heating and cooling system.
  • Keep the areas around air vents clean and free from blockages, dust and debris

Air Duct Warning Signs

If you notice any of the following HVAC issues, your air ducts could be the culprit:

  • Rising utility bills
  • Strange or unpleasant odors whenever your HVAC system runs
  • Evidence of insect or rodent infestations, including noises, odors and evidence of droppings, food or nesting materials
  • Decreased heating or cooling efficiency — even with HVAC maintenance
  • Uneven air flow from different air vents in the home
  • An uptick in allergy symptoms, headaches or other respiratory issues, especially while the HVAC unit runs
  • Strange or new air duct noises, including banging, clanking or hissing


If your air ducts are older than 15 years, it may be time to consider replacement. In addition to cleaning and inspecting your existing air ducts, an HVAC professional can recommend the best type of air duct system for your home. Insulating air ducts may help increase heating and cooling efficiency while protecting your system from damage, so be sure to ask your technician about all the available options. 

Work With Local Duncan Air Conditioning Experts

Dial One Johnson Plumbing, Cooling and Heating has been in the business for over 50 years, providing the best AC service Duncanville, TX, homeowners can rely on. Our team of pro HVAC technicians provides affordable and reliable residential HVAC, commercial HVAC and plumbing services.  

Need HVAC repair fast? Dial One Johnson offers 24/7 emergency support along with financing options to help you get the HVAC repairs you need right away. Visit us online or give us a call at (972) 388-3310 to schedule a visit today.    


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