Lime render and gypsum mix

[shenzou9]

Hi, anyone know what's going on with this ceiling? What's the layer below. Planning to take off the top white layer and skim.

 

[Monkey Boy]

Smoother

 

[Smooth criminal]

Dont waste your time just reboard it and skim

 

[Gilbert75]

Hi, anyone know what's going on with this ceiling? What's the layer below. Planning to take off the top white layer and skim.View attachment 68213

Pva skim, be fine