Slabs and foundations shall be constructed using a slab edge detail that eliminates cracks that could connect the house interior to subslab soil and is consistent with other construction constraints such as terrain. Monolithic slab construction should be used where possible. Only the following slab edge detail options may be used:
- Thickened edge monolithic — the subslab membrane shall extend beyond the outside face of the slab edge.
- Slab poured into stem wall — where concrete blocks are used as slab forms, the subslab membrane shall extend horizontally at least 1 inch (25.4 mm) into the stem wall, but shall not extend upward along any vertical faces of the stem wall. The concrete slab shall be poured into the stem wall to completely fill its open volume to form a continuous and solid stem wall cap of minimum 8 inch (203 mm) thickness. Framed exterior walls shall be sealed or gasketed to the slab.
- Slab capping stem wall — where the floor slab is formed and placed to completely cover the stem wall, the subslab membrane shall extend horizontally beneath the slab to its outer edge. The supporting stem wall shall be capped with a solid masonry unit of at least 4 inch (102 mm) thickness beneath the membrane and the slab.