I have bought some tile effect laminate flooring with the intention of laying it over the floorboards of the ground floor of my house. The shop gave me some 2mm foam underlay which I thought would be sufficient.
On reading the label on one of the boxes, I spotted that I also need a plastic underlay beneath the foam underlay to keep damp and moisture out. Is the plastic underlay really ncessary bearing in mind I have modern timber (but draughty) floorboards and a decent damp course?