Hey guys, I have a job I'm doing that's a bit unusual, a client has an old cottage with a concrete floor, early 1900s house (I'm convinced the floor is newer, however), its about 10m2 that's having a bathroom put in, but, they want a timber suspended floor put in over the top as they want to insulate it and it just makes much more sense for the plumbing side of things. My question is, does the concrete floor which is dry with no signs of mould even behind the old kitchen cabinets need a liquid DPM, my initial thought was that it probably needs ventilation but due to the floating floor height this is pretty difficult to achieve. An outside source has said it should have a DPM put in but I'm now thinking along the lines of does it even need anything at all, it would save some mess. Any advice appreciated, cheers.