The first biennale of the research project AH+ (“optimisation of light weight timber frame constructions”) was finished in 2012. The main goals were to extend and to examine prediction methods and measurement techniques especially in the low frequencies and to develop building guidelines to obtain at least equivalent acoustic protection towards neighbour noise as with traditional heavy constructions. Solutions had to comply with other requirements (fire, structural stability, economic cost, building physics, reasonable architectural dimensions, etc.). Part 6 of this series of presentations discusses constructions and performances of wooden floor constructions. It is especially difficult to obtain good low frequency impact sound insulation in the very low frequencies. The effects of different floating floor systems in combination with suspended ceilings will be discussed.