Home DIY

Thanks, very amateurish compared to your work but given the hard deadline plus doing stuff all new to me probably the most challenging DIY I've attempted so far.

Looking at M20 rubber panels + two layers of acoustic plasterboard - this basically:
https://www.soundstop.co.uk/soundproofing/soundproofing-walls/Sm20-wall-solution4.php

Our house/area is really really quiet but that's part of the issue - the first floor front bedroom will be our room for TV watching so we're more worried about noise from us than from our (very quiet, very considerate) neighbours. But loud conversations/sneezes can be heard through the first floor walls so we're thinking of this as future proofing.

When I ran the ethernet cables I discovered there's a step from the ground floor to first floor walls and the first floor rooms are effectively slightly wider, so I think it's perhaps double skin brick downstairs and single up, in which case God knows what's holding our loft extension up!

Were they leaking from where the brassware threads into the rads?

Yep, have been impressed by videos/reviews of Loctite 55 but if that doesn't work I'll pick up some Slic-tite!