As some of you may know ive recently had a plasterboard wall replaced in my bathroom. The plasterboard was supposed to be 12.5mm thick and have 2 layers either side, but only 2 x 9mm board was used each side. These boards were screwed to the timbers. Im a bit concerned about the thickness of these boards being able to support tiles sized 17" x 12" weighing in at 2.3kg each. In an earlier post i was told that plasterboard with a skim of plaster would support 20kg,s a sq metre but no board thickness was given. Can somebody put my mind to rest over wether this board is going to be up to the task . Thanks.