I'm going to build up my walk-out basement with leca blocks and on top of that cast a concrete slab. The problem is that it needs to connect to my existing house where we've demolished the foundation wall (currently supported by steel beams and supports). I thought we would slide the lower slab under the existing sill and then build straight up so that my old house rests securely on the new slab + leca wall. But now I realize that if I do it this way, the upper slab (concrete slab) won't have anything to rest on. How do you solve this? Anyone creative with a solid suggestion?
