repairing paramount wall

[Mads100]

I am refitting the bathroom, and have removed the (two layers of) tiles but unfortunately not without damage to the awful paramount partition board that’s underneath (plasterboard glued to cardboard honeycomb filling with virtually no studs). There are a handful of bigger chunks that have come out, the worst of which you can see in the photos attached, and some smaller dents. None of the damage has gone deep enough to expose the cardboard innards but it must be close in places. There is no skim coat on the plasterboard.

Is this damage significant enough that I have no choice but to replace the board before retiling? I have read that some people saw the plasterboard away from the egg box cardboard within and then hollow out space in the cardboard to insert studs before replacing the board which might be what I have to do but I am desperately hoping that there is some alternative way to repair the board instead. The bathroom is tiny already so building a stud wall in front while leaving this one intact would not be possible.

I plan to use 300x600 porcelain tiles that are 6mm thick. According to the website they weigh 19kg per sq m. not including grout etc.

Thanks in advance.

 

[Dave]

As long as it hasn’t lost it’s strength/rigidity, then it’ll be fine.

 

[Bond]

I would be tempted to, prime and skim with cement based adhesive and imbedding glass fibre render mesh into the adhesive.

 

[Mads100]

Just wanted to say a belated thank you for your replies! They helped reassure me that I wouldn't need to rip the whole wall down... phew.