Is hard tile affixed to the slab Common Property?

Hi Flat-Chat

Context:

The unit above me installed hard tiles on to the slab with the Owners Corporation permission subject to conditions of consent.  The hard tiles are in a rumpus room above my bedroom and the room above is not a kitchen, laundry or bathroom.  

Two independent acoustic reports have been conducted measuring the noise transmission about 54 LnTw.  When the noise tests were conducted, the tapping machine made a great deal of noise on the hard tiles but was undetectable on the previous original carpet, such that the acoustic engineer had to physically check the tapping machine was operating.  I am regularly disturbed by noise.  Our strata has a recent by-law mandating that the LnTw must be 40 or less.  The EC fail to take responsibility for giving permission or ensuring compliance with conditions of consent for these works.  This EC is generally reluctant to enforce by-laws in this strata.

Question:

1) Is hard tile affixed to the slab Common Property?

2) What legal precedents support the answer to 1) above?

3) If it can be shown that the OC is responsible for the resultant noise problem, how do I strongly encourage them to remedy the flooring back to my original amenity of less than 40 LnTw?

My experience with a popular strata specialist firm was that they;  added little value, research or strategy themselves, played devils advocate arguing against any research I supplied and pretty much just charged me for reading my emails and processing forms.  It is my present assertion that the OC are responsible for the flooring noise problem, at least by way of giving permission for it and should therefore remedy my amenity to the previous carpeted state of less than 40 LnTw.

The problem of course is that they quietly resist and obstruct taking responsibility to remedy the situation and I'm seeking guidance on how to strongly encourage them to fix the problem.

I would value your comments or references to any relevant legal precedents establishing hard tiles on slab as common property.