GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter 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

Installation details for inner corner trim over rainscreen and foam

nhbean | Posted in Green Building Techniques on

Does anyone have advice or details for installing exterior inner corner trim when using a rainscreen over foam?  I’m trying to replicate the historical details on our house that used a 1″x1″ nailed into the inner corners and then butted the siding up to it.  We’ve added 2″ of polysio and a 3/4″ rainscreen of 1″x4″ furring strips.

Do you just build a corner of 1″x4″ or 1″x6″ material to use as a nailing base, and nail the 1″x1″ into that corner, then screw the whole assembly to the studs through the foam?  Or is there another approach that makes sense?

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


    Whether you pre-make the whole inner-corner assembly , or just nail the individual pieces on one at a time is really a preference - both ways work well. When you install the siding remember to bed it in a bead of caulking against the corner trim as you go.

  2. nhbean | | #2

    Will do Malcom - thanks for the advice!

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |