Hi all We had a massive leak in a newly purchased house which caused all sorts of damage. I found that even after clearing everything up there was a persistent damp patch on the kitchen floor, and horrible white mould growing - see pics. I got a handyman in with a jackhammer and cut out a section of the floor. Luckily it wasn't another leak underneath but mostly likely trapped moisture in the concrete and what was underneath it. I now need to fill this hole up, and get it back into a position where the kitchen fitters can level the floor. My question is - what is best to fill this hole up? Ideally I want something that doesn't absorb moisture. It's an old house probably with no DPM. Would gravel, and then concrete be OK? Thanks.