Re: Forget the risk of fire spreading through the holes in the wall
>Plasterboard should never be used as a structural element in a house - mainly because it isn't a strong material.
But it does, the ceiling of many modern houses and particularly those of the 1970~80's it performed a purpose in helping to stop the joists moving, as does the floor over the joists. Okay I note sometime in the 1990's the building regulations were revised to improve the size, spacing and number of noggings and the way the joists attached to the supporting walls. However, the floor without attached plasterboard ceiling and flooring boards is a lot less stiff than one with them attached.
Not kept up with building regulations, but wouldn't be surprised if they do not expressly prohibit the use of plasterboard as a structural element...