Water proof adhesive

[Atlas]

Hi Can any one help please -
I'd like to dot & dab plasterboard onto a 3:1 sand cement render, and I'm trying to track down a suitable adhesive that won't transfer any moisture or salts through to the plasterboard. Also using a salt retardant additive.
Many thanks

 

[markwilsonplastering]

Afraid not pal. You can only waterproof cement.

 

[carlos]

Dab over a cavity drain membrain or batten and board.