Expansion 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 DIY Users.

“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.

Yousan’s Expansion  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 Yousan’s Expansion  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.

Yousan’s Expansion 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.

The Application of Expansion tape?

Sealing of construction joints such as those in windows, doors and facades.
Sealing of expansion joints in facades.
Windproofing of joints and roof linings.
Acoustic and thermal insulation of prefabricated buildings and timber frames.
Alternative or supplement to polyurethane foam (the use of the expansion strip during the installation of windows creates a well-finished edge on the outside, which guarantees watertightness and at the same time forms an effective barrier for the possible application of polyurethane foam as additional insulation).

How to Install Expansion tape?

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.