Hi there, I have a non standard construction extension in a holiday house. It's pretty sound there is a concrete slab floor that is sound and that meets a concrete upstand all round. The while extension is just bordering being below ground level outside so the whole area has been tanked with KA slurry. There are no airbricks to the outside it is a fully sealed area. It's now time to put in a floating floor. Do I need a black plastic sheet DPM or is that now irrelevant because of the tanking? The floor is treated 3 X 2 on those adjustable load bearers followed by water resistant chipboard. It's a holiday house ... Do I need to insulate the floor? It will be a lounge room with a sofa and an electric log burner. Will condensation be an issue in the floor or am I ok? Many thanks Bron
