figure 4-13

Figure 4-13. Slab-on-Grade with Masonry Stem Wall and Interior and Slab Insulation

Figure 4-13 illustrates a slab-on-grade foundation with a concrete masonry foundation wall. Rigid insulation is placed vertically on the interior face of the foundation wall and extends into the joint at the slab edge. This solution can employ insulation at the stem wall only, which isolates the slab from the exterior side of the foundation, but does not isolate it from the subslab grade.  Insulation may be placed under the slab (as shown) for additional thermal or condensation control.  This example shows a 2 x 6 above-grade wood frame wall with cavity insulation.