Fibreboard under selfadvesive underlay

[szmulik]

Hi
I would like lay solid wood tongue and grove floorboards on my on wood floorboard.

I want use 5.5mm fibreboard to evened wooden subfloor and get sound insulation. On fibreboars I want lay selfadvesive underlay and then solid wood floor.

Can I use selfadvesive underlay over fibreboard or better idea is use 5.5mm plywood instead of fibreboard?

 

[Doggit]

It'll depend on how uneven you're wooden floors are, as to whether you can just lay the fibreboard down, or you need ply, and then feather edging compound to even it out. Assuming that the wooden floor is fairly flat, then just lay the fibreboard, and then the solid wood floor on top of it; it will act as an underlay, so you don't need the self adhesive underlay - not that it would stick to it though.