I am replacing my old laminate flooring with new. I have had a look at the old underlay and it "looks" fine. It's green fibre board on top of the wood floor boards, on ground floor. Is it ok to leave these fibre boards in place and reuse? Or is it best to use new underlay, regardless of it looking fine? If so, what would be the best choice between fibreboard, or something like Sonic Gold?
