The nail-down flooring need to be nailed to an additional subfloor layer. The subfloor layer should be thick more than enough in order that nails don't protrude. The Iso-Phase® flooring underlayment would reside beneath this layer, totally free from any penetrating nails. The technical storage or access is strictly needed https://zanderomuzc.blogocial.com/the-basic-principles-of-acoustic-floor-underlay-74721995