I am about to lay an engineered wood flooring over part timber floor boards and part karndene covered concrete floor. both floors are in good condition and level, although there is a very slight difference in level between the wood and concrete floor.
i have been given conflicting advice/opinions regarding underlay. some have recommended no underlay and pinning the floor so that it isnt a floating floor while other a 6 mm fibreboard or 6mm ply.
i will be removing the skirtings and cutting in around door frams while ensuring i leave a gap for expansion but just not sure whether i need to lay a subfloor?
any advice will be greatly appreciated.