Another garage/base question

[ScottishGasMan]

my sectional concrete garage that I would like to replace, it's 6m x 3m and sits on a concrete base.

I've not dug down to see the depth of the base yet, but at one point where the level of the ground is lower you can see at least 5inch of depth of the base.

Is it a reasonable thought to think this could take the weight of breeze block?

My idea is to make a single skin building from the lightweight thermalight style blocks and get a family member to rough cast the exterior to make it water proof and yet keep it lighter than concrete block.

 

[noseall]

It's not unusual for the exposed edges of a cast slab to appear thicker. I personally would not risk the weight of the masonry plus roof on a presumed thickness slab. If you were building from scratch you would have thickened the edges of the slab as well as added some mesh to tie the edges in.

I'd get the digger in and hoof the lot out and build strip foundations. Building off a slab is a poor and unreliable way to construct a garage. Water seepage at floor level is always a risk.