I’m replacing laminate flooring in hall and full down stairs. Laying hall first as it runs in a different direction. Under the existing laminate I had 3mm foam on top of plywood nailed to existing floorboards. When laying the new Engineered flooring should I keep the foam underlay? Also I’m not planing on having a floating floor. The flooring is 14mm thick tongue and groove what’s the best way to fix flooring down either stapler, Porta Nailer or lost-tile screws?