GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Performance Tape for Arlington InBox with Flanges

pico_project | Posted in General Questions on

Using 4″ Siga Fentrim to tape/flash our house. I put in two Arlington InBox exterior outlets. They are the new construction style with flange for stucco and Hardie. 

Since these were low to the ground I was thinking about not taping the bottoms. Everyone else at the site thinks they should be taped on all sides. My thinking is drainage and that’s how windows are done with flanges. 

They were installed after the WRB. Siga Mavest 500 SA.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Expert Member


    I'm with the rest of them. This is more analogous to pipes or conduit penetrations, not windows. Tape all four sides or use a piece of Peel & stick with the hole cut out.

    1. pico_project | | #2

      They are square with an extended flang. Instead of round and smaller diameter than the opening. I would say they're more like a window than a pipe. :p

      1. Expert Member
        MALCOLM TAYLOR | | #3


        We leave the bottom window flange unsealed because we have provided a drainage plane below it with tapered sills and sill pans. Electrical boxes - like pipes - have no mechanism to move water to the unsealed bottom, or to move it to the exterior from there.

  2. Patrick_OSullivan | | #4

    I have a bunch in my house and they are all installed like little windows. This means, that in addition to the bottom being unsealed, the "rough opening" is flashed, and then the whole thing is air sealed on the interior.

    It's probably not worth losing sleep over, but if the thing ever developed a crack in it, I'd rather the water have a means to get out.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |