Our house is like a tinder box... if your upstairs you can hear people talking and the TV ect... also if your downstairs you can hear every creak and bump from upstairs..We're having a full rewire done which will require lifting the upstairs floors. Whilst the floors are up we were thinking of insulating between the joists in order to dampen the noise and also hopefully make the place a bit warmer... what materials am I best using for this? we were looking at using rock wool ... are there any downsides to this kind of thing?...ive uploaded a photo of the cavity