Por968t

Hi all, new here, have a question, I've got a 8x4m concrete slab 10" thick and reinforced, id like to erect a timber garage on it, the question is, whats best to put directly onto the concrete to build the walls off? I don't want to build a block or brick wall, but also don't want the thing rotting out? The walls will not be to the edge of the slab, about 250mm in each side.