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

Insulation of the interior stem wall

ron_marsh | Posted in Energy Efficiency and Durability on

I am building a 40×60 metal workshop. It is slab-on-grade and I had specified 2″ rigid foam on the interior of the stub wall, thus creating a thermal bridge between the foundation and the slab. The footing and stem wall have just been poured. I think there has been a mis-connect between my contractor and myself because it looks like he is going to place 2″ thick rigid foam only in the space between the footing and the slab (i.e. the 4″ slab will be “faced” with 2″ thick rigid foam… in other words, the foam will extend from the top of the slab to the bottom of the slab, but will not continue down the stem wall to the bottom of the footing. I live in Oklahoma, Climate Zone 3 and the workshop will be in constant use. Is this acceptable, or will I lose most of the benefit of interior insulation of the slab wall by not extending the 2″ thick rigid foam downward to the bottom of the interior stem wall? Sorry for the looonnnggg question, and thanks for any assistance.

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. kevin_in_denver | | #1

    The stem wall can be insulated on the outside before backfill.

  2. GBA Editor
    Martin Holladay | | #2

    The way you specified it was better than the way your contractor wants to do it. For more information, see:

    Slab Happy

    Insulating a slab on grade

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |