Plaster indoors, primer mortar?

[RikardB88]

I am going to plaster walls for an upcoming bathroom. The walls are made of concrete blocks and leca. I'm planning to use Weber 224 plastering mortar C.
The question is whether I need to apply a primer beforehand? Or is it enough to wet the wall thoroughly and then start plastering?

 

[Alexn72]

Since you're going to cover the plaster later, I would say that gb doesn't have much of a function. But make sure there's moisture in the walls so the plaster doesn't dry too quickly.

 

[RikardB88]

Since you will cover the plaster later, I would say that gb doesn't have any major function.
But make sure there is moisture in the walls so the mortar doesn’t dry too quickly.

We'll do that. Thanks for the reply!