Hi Moonfleet
I have had this problem before I found a concrete floor in the kitchen which had a cupboard that’s where cabinet went.my mate now owns this house and he has bolted it to the floor in to the joists.
my cabinet is in the loft bolted with coach bolts to the joists I have had no problem with damp as some folks say 15 years now no problem
it just has to be secured to something
good luck