Sound insulation in a flat

[handyman77]

We are refurbishing a flat and just laid a engineered floor after ripping up a similar floor. The client supplied a high spec underlay.
The builder that works downstairs has informed his client that we are in breach of building regs and that we should put.....
Rockwall between the joists
Soundbloc rubber matt. 3mm
Sound deadening board such as Karma easy panel
Another layer of rubber soundbloc matt.
Prior to us removing the floor, there was no underlay at all.
Any ideas? Are in breach of regs?

 

[harry0harry]

Is this a leasehold flat ?

 

[tony1851]

Ignore him - you are not in breach of any sound insulation regulations.