Hi Having a new engineered wood floor fitted. fitter has recommended floating, but the subfloor is creaking in places. its a new build and the subfloor is also floating on kingspan , look like they are large sheets of mdf type material and look glued together. He thinks the floor will hide the squeaks once fitted, but does it need sorting first and if so how. I'm only familiar with joists and would screw down some more, but he can't screw into kingspan.