R403.3.2

Section R403.3.2 is titled 'Protection of horizontal insulation below ground' and covers requirements for footing construction. The requirement to protect below ground horizontal insulation of specific depths and/or dimensions with certain materials for frost-protected shallow foundations is established. The purpose of this section is to prevent structural failure (due to loss of frost-protection).

The model shows a translucent slab installed over horizontal insulation which extends outward more than 24" from the foundation it is protecting. (Fill is not shown for clarity).