Read the membrane route with Figure 4.2.8 and the applicable replacement wording.

The national and NSW provisions require the bottom of the slab to be entirely underlaid, continuing under internal and edge beams to finish at ground level in accordance with the figure. SA wording addresses entire underlay and extension under edge beams. Do not turn one termination line from one illustrated alternative into a universal detail.

Clause 4.2.9 separately addresses edge rebates for slab-on-ground and stiffened raft construction with masonry cavity or veneer walls. The rebate is at least 20 mm and is flashed and drained in accordance with H2D4; where it cannot be flashed, it is filled with mortar. Read that complete condition, not a convenient fragment.

The explanatory note says rebates are not required for single-skin or framed walls with external cladding, and points to 4.2.21 for minimum edge-beam details. A recess dimension does not alone settle beam size, wall support, flashing, drainage, levels or termite interfaces.