Hi folks. I recently purchased some sound proofing plasterboard and am a bit concerned about the weight. 28kg boards & 1200mm square. I am trying to fix six boards i.e 3 wide by 2 high. They have a rubber back and look pretty good.. Its a party wall at first floor level which is drylined. So already plasterboarded and sounds like timber battens to a masonry wall. I didn't want to remove the current plasterboard wall and having discussed with the supplier, I understand that reasonable results can be achieved by fixing the boards to the plasterboard. So given advice on fixings and reasonably happy about the process. My concern is with adding the extra weight to the pre-existing plasterboard wall. Have searched the internet but nothing really about adding weight. And these are heavy. I appreciate that perhaps taking down the current plasterboard might be the best option but am trying to avoid if possible. Any thoughts would be appreciated.