By M&S Air Conditioning on Thursday, 04 February 2021
Category: AC Blog

Can I Use Duct Tape to Seal My Ducts?

The product we now call “duct” tape was originally manufactured by Johnson & Johnson’s Permacel division during WWII.

The military needed a waterproof tape that would keep moisture out of ammunition cases. For this reason, the original “duct” tape was only available in army green.

Because it was green and shed water (like a duck), WWII soldiers began calling it “duck” tape and, due to its waterproof nature, strength and built-in adhesive, they soon began using it for all sorts of repairs - even using it to close wounds in a emergencies!

So how did it come to be associated with duct repairs and become predominantly silver?

The returning soldiers brought with them the green “duck” tape as well as a housing boom. This prompted savvy manufacturers to begin selling the miracle adhesive as a way of connecting heating and cooling ducts in many of the homes being built. To that end, they changed the color to silver and it quickly became known as “duct” tape.

To this day, many homeowners believe they can fix just about anything, including their home’s heating and cooling system, with a few layers of duct tape, but don’t do it…

Duct tape has lots of great uses, but fixing ducts isn’t one of them!

Extensive tests done at the Environmental Energy Technologies Division of the Lawrence Berkeley National Laboratory concluded that under normal or stressful conditions, duct tape used on ducts turns brittle and fails. The popular adhesive tape failed every test the lab put it through—often catastrophically. In fact, the state of California has banned the use of duct tape on ductwork, and many building codes across the U.S. prohibit the use of duct tape as a solution to ductwork problems.

Commercially available duct tape can burn and produce toxic gasses, and that isn’t something you want attached to the ductwork that carries the air you breathe!

Professional HVAC technicians sometimes use tape in their work, but it is not what we have come to know as “duct” tape, it’s a specialized aluminum or metallized tape. More often than not, they rely on mastic sealant, a resin-based adhesive, to perform duct repairs.

If there’s a leak or break in your ductwork, don’t reach for the duct tape, reach for the phone!

Call M&S Air Conditioning & Appliance Services at (561) 861-3345 at the first sign of trouble.

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