Carpet underlay for wood/concrete floor?

matty_hunt

Hi. I want to put new underlay down to hopefully improve thermal conditions in our living room. It has old rubber waffle type of underlay at the mo. The floor is concrete with wooden planks laid loose on top. (1930s) Never seen this before! The planks are painted black but just seam to sit on the concrete. Some planks have warped and rock when walked on. I was going to use the new foam type underlay. Cloud 9 Cumulus 11mm (3.1 tog) or similar. (have read to only get branded foam as the cheaper ones are lower density, regardless of what they might say) Is this suitable for this type of floor of do I need the moisture barrier of the old rubber types? I see felt underlay is warm and cheaper than foam but have no experience of it. Any advice appreciated. Thank you.