Hi. I'm installing a floating floor over hardwood flooring (there is reasonable sound-proofing under the floor between the joists) and have purchased Bunnings "Smart Home Products 9.5mm 2.887m2 Soundguard Acoustic Laminate Planks - Camomile". I've also purchased Bunnings "Qep 2mm Ixpe Acoustic Pro Underlay" and several sheets of 6mm villaboard. All up, the 17.5mm is within my 18mm limit for height of the new flooring, and the 2mm underlay is within the requirements of the planks' warranty. My issue is, I'm unsure of whether to install the villaboard first or the underlay first. I'm inclined to install the villaboard first, securely attaching it (not floating) to the wooden floor (the wooden floor is in reasonably good nick, and reasonably flat) siliconing all joins and edges creating a very flat sound barrier. Then install the 2mm underlay then the planks (keeping the sound absorptive layers together). Alternatively, I could install the underlay first, then float the villaboard on the underlay, again siliconing all joins and edges, then the planks. Any thoughts most welcome.