i’ve finished reducing my levels to allow a new concrete slab, insulation, UFH, screed. My concrete slab needs to be to the top of the timber in my photo. How should i go about avoiding filling in the cavity? Or would it be easier to raise a full run of blocks on the internal leaf and just concrete to required height?
I’d simply lay another course of cropped concrete blocks to the height you need. Brick ties are already in place and looks like whoever laid the blocks was expecting another course but wasn’t sure what height was required at the time.