Hi, we used a system supplied by a company in Athboy, Co. Meath. The product is a sort of anti-fire/insect etc. woodchip wool-like substance that is 150mm tick and lays in between the floorboards (its also an insulator). Then if you want the full bells and whistles, they also supply a material that sits in the joists of the roof (about 25mm in rolls, could be cork) that you then put your ply/flooring on..I'm only new here so I don't know if I can give the name of the company...