Photograph 4 is a thing of beauty.
Thermal break for concrete floors.
The thermal break insulates the interior floor slab from the exterior exposed slab edge while transferring the loads imposed on the exposed slab edge back to the interior floor slab.
A schöck isokorb structural thermal break is a fabricated assembly that is cast into the concrete floor slab at the location of the building insulation layer.
The sides of the concrete slab also referred to as the perimeter wall is often forgotten or not considered at all with respect to the thermal envelope.
A thermal break worthy of great artisans.
Concrete placement shows concrete being placed on the top of the sheet polyethylene and a layer of xps insulation.
The thermal breaks consist of a graphite enhanced expanded polystyrene module with stainless steel rebar running through the insulation for tension and shear resistance.
Stones gravel keep the plastic from blowing away.
Notice that there is no welded wire mesh.
A thermal break to the perimeter of the floor slab between the slab edge and the foundation greatly increases r value.
The bars tie into the rebar.
In older details a timber strip was used but branz bulletin 576 edge insulation of concrete floor slabs shows a new detail that incorporates a 10 mm thick strip of xps with an r value of r0 25.