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

Foam glass gravel

user-7022518 | Posted in Green Products and Materials on

Has anyone used the foam glass gravel for under slab and exterior foundation insulation? There is a plant south of Philly which supplies to Virginia. The recent Green Building Advisor article on the product mentioned R values that were 11 to 15 R per foot. I wonder what happens to the R value when water or soil enters the aggregate.


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

    Do you really wonder?

    The thermal conductivity goes up (and the R-value goes down), of course, just like any other insulation material that gets water saturated or filled with dirt.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |