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Community and Q&A

Recommendation for window flashing tape?

Myrtleboone | Posted in GBA Pro Help on

I am in the process of shopping for window flashing tape and am running in circles about what brand (and type) of flashing tape to purchase. Obviously, price is a consideration, but I do not want to sacrifice quality and longevity.

I live in northern Maine, so low operating temperatures are critical. I have read that rubberized asphalt becomes brittle in colder temps, whereas butyl rubberized flashing does not (not to mention VOC off-gassing). Polyken Shadowlastic Plus seems to be a good bet (20 or 35 mil?), however, Siga Wigluv seems to be all the hype (but only 2.4 inches wide) but recommended by my window dealer. Vycor Plus was initially what I wanted to purchase due to its availability in big box stores and a relatively lower price, but the high VOC content and questionable cold weather performance is worrisome. Also, recommendation for width on the vertical and bottom strips?

I paid a lot for windows, and want to seal them well. Thanks in advance.

FYI, I have read the backyard tape articles but would like a more specific recommendation pertaining to my application. Thanks.

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  1. roygoodwin | | #1

    Siga Wigluv is also available in 6" (150mm) & 4" (100 mm) -- see "The single-sided high-performance adhesive tapes Wigluv 100 and 150 have all of the same benefits of Wigluv 60 in a wider format. " But NOT cheap or inexpensive.


  2. user-1061844 | | #2

    For flashing the window sill, we at 475 recommend EXTOSEAL Encors - it is a butyl adhesive modified with acrylate, so unlike other butyl tapes works in freezing conditions (down to negative 4F). It adheres very well to most building materials, including concrete, OSB, ply and woodfiberboards and is self sealing around nails and screws. For more info see video of Chris Corson using ProClima's ENCORS or contact us for a sample.

    Since your high performance window do need to be air- and watersealed on the sides and top as well, but this tape would be wider and more robust then needed in those places - we recommend using one of the other ProClima vapor open window tapesProClima window tapes for that - for face taping the split release paper TESCON Profil, or for pre-taping window frames before installation - CONTENGA EXO or SL.

  3. GBA Editor
    Martin Holladay | | #3

    Here's my advice: don't obsess over this decision. Careful installation (using details that depend as much as possible on lapping rather than the strength of the tape adhesive) is just as important as, or more important than, your choice of tape.

    Here is a link to an article I wrote on the topic. While the article is somewhat out of date -- it was written before European tapes were commonly available in the U.S. -- it includes useful background information: Choosing Flexible Flashings.

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