Semi-detached, noise from neighbours is too much (dog howling when they leave it at home, neighbours shouting at dog to stop barking when they're at home, older kid playing games console, younger kid crying and shrieking, adults sneezing, home theatre, you name it) yes I know the real answer is move to a detached house!
I understand that getting decent improvement is tricky so not expecting miracles, but I have to do something. Party wall is a double skin brick, joists run front/back so no pockets for them penetrating the wall, while doing other work on the house I've noticed the bricks are laid frog down, so the wall is effectively an array of air-pockets which probably doesn't help, wouldn't surprise me if builders had used brick on edge in various unseen places, or skimped on mortar. I suspect cable drops for aerial, mains and corresponding back-boxes are in same place on opposite sides of the wall reducing effective depth in places.
Anyway, I've recently increased width of the lounge by 1m (by subsuming most of the hall) so I don't mind loosing 3 or 4" to some insulation.
Is any of the heavy slab insulation, e.g. worth bothering with, reviews seem to rage from "shit" to "brilliant".
Or what about the rubber sheets, e.g. any cheaper sources of thick rubber on a roll for DIYing?
Couple of staggered layers of plasterboard on top of either of those, anybody had worthwhile results?