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

Can I use rigid styrofoam on top of top plate to minimize thermal bridge from trusses

Stephane Aucoin | Posted in Green Building Techniques on


I was wondering if its suitable to install a truss on top of a sandwich styrofoam between 3/4 ply and the top plate of an exterior wall, Sort of like putting a SIP on flat. Can the SIP support the point load of trusses for lets say a roof needing to support 100 psf?


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
    Dana Dorsett | | #1

    You can, but you would have to have an engineer run the numbers and specify the the fasteners, along with the minimum density of the foam. I'm not sure what horrific thermal bridge probably you'd be solving with that approach. In hurricane zones the thermal bridge of the required framing ties would defeat any gains at the margin of thermally breaking the timbers.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |