Thanks for the advice...originally I was going to do without the underlay but on closer inspection there is some levelling required; particularly around the concrete hearth.
Any particular underlay that stands out or more importantly, any to avoid?
LS
Hi
Firstly, great site, dip in a lot but my first post.
I intend to tongue tite 18mm engineered wooden floor onto 6mm plywood screwed to existing 18mm floorboards. 6mm ply is used to even out the existing floorboards.
Question 1: do i need underlay i.e existing wooden floorboards ->...