ᐅ Potato Cellar – Foundation Slab – Construction Layers

I have a room in the basement, kind of like a root cellar, about 12-14 square meters (130-150 square feet). It’s all unfinished, and I’d like to set up a sort of workshop there. My next step would be to plaster the walls to make it feel a bit more cozy. The tricky part is the floor: the slab in the middle is split. On the left side, there’s a concrete slab, but on the right side, there’s just bare earth. I’m not sure why the previous owner did it that way. I want to level and fill the half with the bare earth to match the concrete slab. How should I approach the construction sequence? Should I dig out to the level of the slab, install a waterproof membrane (like a bituminous sheet) in the earth-contact area to protect against potential hydrostatic pressure, and then fill it with a concrete screed up to the slab height?

Thanks for your help.

Why? Because of storage durability.
How is the room sealed against moisture from the outside?

This is a house built in 1959, with barely more than a bitumen layer applied. The room is intended to be next to the workshop, serving also as storage space for it. I don’t want to place the items directly on the bare ground.

I am afraid the same thing will happen as in our tractor garage. Moisture got in, and the plaster had to be removed again. The bare wall handles moisture better without plaster.
We put the shelves on the clay floor in our old cellar. It is dry and has been fine for a long time.

Peter Silie schrieb:

bare soil on the right, for whatever reason the previous owner did it that way back then

To maintain natural humidity levels in the basement. Once you seal the floor, that’s no longer possible. I used garden gravel as a clean layer on top and relocated the originally planned workshop (due to the expected sawdust) to another room.

haydee schrieb:

I’m afraid the same thing will happen as it did in our tractor garage—moisture issues, and the plaster had to be removed again. The bare wall handles moisture better.
We place the shelves directly on the clay floor in our old cellar. It’s dry and has worked well for a long time.

I can definitely leave the wall as it is, but how should I proceed with the floor? I want to make sure it is weatherproof, including protection against rising damp.