Soundproofing wall

always_sunny

I am looking at soundproofing a common wall (terrace) as my neighbour is getting a bit noisy, nothing major but I would like to have it addressed.

Has anyone tried the 15mm Knauf Soundshield Plus Plasterboard or similar sold at B&Q and co?

I am not expecting miracles, just some reduction of noise/tv coming from the other wall and hopefully also stopping my noise going over there.

Davesnave

Yes, I used the 12.5mm doubled-up, with added rockwool for stud walls. Works OK, but we are a bungalow with solid floors, and as we're detached it's only our own noise we're blocking!

antilles

Yes - there was a similar thread a few days ago, have a look here: https://forums.moneysavingexpert.com/discussion/5935826
I used Gypoc Soundbloc from B&Q, 2 layers of 12.5mm, dot and dab each layer over party wall, and plastered over this. Added over an inch of mass to the wall. I'll be honest and say I was very disappointed with the results. I didn't notice any significant difference in noise reduction, maybe a tiny bit. The main issues you have (which I found afterwards) is that flanking noise will travel around the wall and down through the ceiling, and that if the walls are thin in the first place, adding more mass doesn't seem to make any significant difference, at least it didn't in my case. Would be interested to see if you see any different though - there may well have been things I could have done during the installation that I wasn't aware of.
The boards are very heavy as well and it was a 2 man job moving them around to make sure they didn't break.