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.