Ask the Expert: How to Use Expanding Foam Tape


Have you seen our Expanding Foam Tape on the hardware store shelf and wondered what it was for? To kick off our new “Ask the Expert” series, we sat down with Frost King’s VP of Marketing and foam tape guru Ben Sanders to learn what Expanding Foam Tape is, when you should use it—and why it’s a game changer.

So, What Exactly Is It?

Expanding Foam Tape is a type of weatherstripping that has been available for commercial use for a long time, Sanders told us, but is a recent addition at the retail level. And it can make all the difference for home DIYers.

“This product came about because people were having trouble building pole barns. They couldn’t find a sealant that could completely seal the range of gaps in corrugated roofing,” he explains.

Frost King’s Expanding Foam Tape meets that need by doing exactly what the name implies: it expands to fill uneven spaces. So, for example, if you have a 150-year-old home with the original door, you may have a large gap at the top of the door frame and a smaller gap near the floor because the house has settled over time. With a traditional foam tape, you’d have to cut individual pieces of tape and layer them to fill larger gaps. But Expanding Foam Tape is compressed and can grow to fill cracks anywhere from ¼-inch to 1-inch wide. As it expands, the tape conforms to the space, creating a watertight seal that’s resistant to bugs and vermin and can withstand temperatures between -40° F to 212° F.

Where Can You Use It?

“Our Expanding Foam Tape has excellent insulating and sealing properties and it’s lightweight and stable, but incredibly dense,” Sanders says. “You can use it in any application where you’d use foam tape and it will do a better job because it’s so much denser.”

In addition to the traditional places where you’d use foam tape—think around doors, windows, rooflines, soffits, gaps between the house and a covered patio—Expanding Foam Tape works very well around hard-to-seal, uneven surfaces, such as areas where concrete meets wood. It’s also self-extinguishing, so it won’t ignite in a fire.

How to Install

Installation is as easy as any other foam tape. Here’s what you do:

1. Start by measuring the space where you want to put the tape, and cut a length to size.

2. If you’re weathersealing a vertical space, start at the top and work your way to the bottom. Unroll a foot of tape at a time, removing the backing as you go, and insert the tape into the gap. Try to work quickly, because the foam will begin to expand as soon as you remove it from the packaging.

And that’s it! Project accomplished.

Frost King’s Expanding Foam Tape can be found at Home Depot, Lowe’s, Walmart, and other retailers that sell our product

Disclaimer: The information provided in this blog post is for educational and informational purposes only. Homeowners should always consider safety precautions before starting any home improvement project.  While we strive to offer accurate and helpful advice, Frost King does not assume responsibility for any actions taken based on the information provided or for any consequences resulting therefrom.