......"There was a system used by house builders once that was basically several sheets of plasterboard glued together. Forget about hanging shelves on it though."
My 1988 house has this construction.
The ceiling and the floor had a strip of wood nailed on and then plasterboard was fitted to one side. Scraps of plasterboard were stuck onto the inside face and then another sheet was bonded to it to create the other side.
I am not impressed, athough I have had no problems in practice. In my spare room I have a wall mounted cupboard above my PC. It hasn't fallen yet and has all my discs and protographic stuff in it.
It is very poor at sound insulation.
Is this type of construction still allowed? What was it called? Were there any regulations controlling this type of construction?