For info it's a terraced house, gas pipes to the meter are in this space.
Cupboard under stairs was full of stuff, mostly standing on the floor. I noticed salt crystals on lower bricks and paint flaking, also mold on outer walls (left).
I should have taken a before pic, but this is after tidying it all up, scraping the flaking paint off the wall, and taking up what was a carpet on the floor.
There seemed to be damp patches under the carpet, and the underlay for carpet was quite stuck to the concrete, but not long after tidying the patches seemed to have gone.
I'm just wondering if its due to bad circulation of air, it was pretty crammed, there isn't an air brick in here, so lack of air circulation. But also wonder if damp may be creeping up walls a bit?
Apart from a few bricks which had a bit of a crumbling surface, they are fine now I've taken the loose surface off, there isn't any other signs of real damp damage.
I'm wondering how best to prepare the floor to minimise damp issues again, ideally to put vinyl down on top of underlay due to it being quite rough concrete currently, but could do self-levelling compound and then paint floor?