We have been desperately trying to reduce the noise in a bedroom from people weeing into the toilet above. We are reticent to put a sign on the toilet asking people to wee quietly. So far we have:
1. Boxed the plumbing up with insulation around the pipes
2. replaced the toilet with a more modern "back to the wall" toilet
3. Put a hole in the boxing and re-insulated with self adhesive foam from Bunnings
4. re-insulated the box with acoustic insulation from Bunnings.
My last ditch attempt ( before replacing the toilet with one with the cistern behind the wall which I think is not going to be good enough either) is to add a layer of material over the box. I am thinking of Gyproc Soundchek. We have guests arriving on Thursday and need to get the ceiling looking acceptible by then. Is this Gyproc the best solution or is there a better one. 1 sheet of the Soundchek will do a double layer, is this worthwhile or just over the top?