Sealing ductwork without a professional is possible through a few simple methods. It can allow ducts to more effectively distribute cooled or heated air. Ductwork sealing and repair are part of our indoor air quality services at Grasshopper Heating & Cooling. Professional service can save you in the long run if the issue is substantial. However, if there are just minor leaks in, for example, attic ducts, you can try sealing ductwork yourself to improve comfort, indoor air quality, and energy efficiency.

Here are some easy methods if you want to try DIY duct sealing:

Locate the Air Leak

The first step is to identify the source of a suspected leak. Attic ducts are prone to leakage, so this is the best place to start looking. Ductwork may have been run around joints and bends, leaving it susceptible to damage, or it may have been neglected for several years.

If you find rusted, crushed, kinked, or chewed ducts, it’s time to call a professional. But easy ways to spot a leak include:

  • Place a smoke pen near a duct; if the air is escaping, the smoke will blow in one direction.
  • Spray soapy water on ducts; bubbles will form if air is rising from inside the channel.

How to Seal a Leaking Air Duct

Here are the most common ways homeowners can seal air ducts and minimize leakage:

Duct Tape

Do not use standard duct tape to patch leaky air ducts. It’s not effective for sealing ductwork and will peel away due to temperature changes. Oriented polypropylene tape and aluminum foil tape are much more effective and can be bought at a local hardware store. For the best results, look for a tape rated for use with HVAC systems. For example, foil tape is wide enough to cover gaps and can remain fixed for some time.

The tape is easy to apply. Just take a roll and wrap unsealed duct connections, spaces, seams, and cracks. Any foil or tin tape that is rated by Underwriters Laboratory (UL) is approved for duct sealing.

Duct Sealant

Avoid using duct seal, which is intended for spaces around electrical wires and conduits. Duct sealant is a thick, pasty, paint-like material you can apply directly to cracks and gaps in ductwork. There are a few ways to apply it. You can scoop it out of a pail and apply it directly with a paintbrush. Or, you can use a caulking gun to place the sealant on the desired area. 

Water-based sealants are easy to clean up and hold up well. Mastic duct sealant provides a tighter seal and a more permanent solution. Also applied with a paintbrush or caulk gun, it hardens on the duct and is difficult to remove. Therefore, consider whether the duct will need to be cleaned or disassembled in the near future. 

When applying mastic sealing, remember to clean the affected area, wear gloves and long sleeves, and wear a mask (especially if no fresh air is available).

Should I Call a Professional for Sealing Ductwork?

The two options above are easy ways to stop air leaks. But they’re not always the most practical or effective, especially if you can’t access leaky ductwork. Even if you sealed a leak or two, there may be one you can’t see. A professional has the tools and methods to successfully seal your ductwork no matter where it’s leaking from.

Aeroseal is a proven method that doesn’t require physical access to the leaky duct. It also doesn’t require removing drywall. The product can only be applied by a trained professional and is suited for any kind of duct. To use it, the technician will find one access point to inject a liquid rubber sealant. As it’s distributed throughout the duct system, it will automatically fill any holes, cracks, or loose connections.

Sealing ductwork will keep the air in and dust out. This applies to both supply and return air ducts anywhere in your home. 

Contact Grasshopper Heating & Cooling

There are a couple of DIY duct sealing methods that won’t cost you much. While they can do the job for a while, a professional can offer a more permanent solution. Leaky air ducts can cause a variety of indoor air quality issues in your home. However, we can find the source of the problem and determine how to resolve it. For more information on sealing ductwork and other ways we can help, call Grasshopper Heating & Cooling at (518) 241- 1762 today.

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