Vibrating Residental Floor, 150mm THK. R.C, 4x6m Spans, Internal Bay 1

[YuleMsee]

Need advice on the simplest method of stopping that slab from vibrating, vibration is felt just by walking. Owner needs to the sell the unit and it chases away potential buyers.
Answers I've got so far,
1. Increase depth of screed and re-do the floor finish.
2.Introduce a steel beam below bolted to existing beams and slab to cut the span in half

 

[271828]

Need a lot more information. Is this a wood floor? What's the span? Does the vibe build up during several footsteps or is it impulse responses to individual steps?

 

[Luceid]

Some of that was in the title, looks like 150mm reinforced concrete with 4m x 6m bays

 

[canwesteng]

Option 1 isn't likely to help. Option 2 could help, but depends on the stiffness and span of the beam.