Canned spray foam and liquid sealants are the usual go-to products for air-sealing around windows, but Hanno offers another option: Hannoband. Essentially adhesive-backed strips of foam, which are sold in different widths and thicknesses, Hannoband is adhered to the outside of a window frame prior to installation in the rough opening.

The foam is available in a variety of maximum-expanded thicknesses for gaps anywhere between 3/32 in. and 3/4 in., and thinner foams can also be stacked to fill a wider gap—a nice workaround for situations where rough openings may be inconsistent. Once unrolled, the foam is designed to expand very slowly, so there is ample working time to set and adjust the window before it reaches full expansion and the gaps close up. Because the tape has multiple separate rows across its width, it boasts claims of redundant air-sealing.

Perhaps the most appealing trait is that the tape retains its compression and expansion over the long haul, so movement in the structure will be less likely to create future air leaks. But before you daydream about using the foam to create a reversible seal in, say, a rough-masonry opening, know that there are limits to the foam’s ability to conform to irregular surfaces, and smoother is still better. Prices start at about $1.45 per lin. ft., and vary by size.

www.hanno.com

—J.F

From Fine Homebuilding #289

More about air-sealing:

Air-Sealing a High-Performance House – A red pen, a plan, and careful air-barrier installation are essential when building an energy-efficient home.

Double-Sided Air-Barrier Tape – Siga Twinet double-sided mounting tape is a popular, though costly, alternative to stapling an air barrier to the inside of roof and wall framing.

Podcast 199: Roof-insulation Retrofit, Codes for Existing Buildings, and Air-sealing Tape Choices