Paramount partition plasterboard damaged

Hi all,
After removing my bath and the tiles above it. I’m left with damaged and muck covered plaster. The wall is a paramount stud that backs onto the main bedroom. once the new bath is fitted, it will be re tiled.




To prepare for tiling, Im thinking remove the bathroom side plaster and the cardboard between the sheets. Put some noggins in and then put a tile backer on instead of plasterboard.
I know the internal cardboard honey comb is there for structure so removing it will compromise the bedroom side. When I add the noggins, can I glue it to the back of the bedroom side of plaster board, as well as screws into the stud frame.

maybe I should fit and dab over it?

Any other suggestions would be welcome.

Many thanks for your help.

sounds like a faff. what about a 2x2 stud ,fixed to the floor and ceiling and bonded centrally to your existing paramount wall for rigidity. then wedi or marmox or similar lightweight tile backer.

That's how I deal with paramount walls if needed. Remove all cardboard and build a new frame in between before boarding over. You'll be able to get the new wall bang on flat and plumb too. I use low expansion expanding foam to bond the back of the studwork to the remaining plasterboard. Studwork centres will change depending on thickness of boards used, 10mm board = 300mm, 12.5mm = 400mm, 20mm = 600mm.