DPM has to be applied / fixed. Apply impact / heath insulation like Rockwool.. min 25mm http://www.rockwool.co.uk/products/u/2011.product/9857/building-insulation/rockwool%C2%AE-slimfloor or http://www.rockwool.co.uk/products/u/2011.product/9905/building-insulation/rockfloor%C2%AE
Rockwool...
