Should I plaster/board behind toilet frame?

[zachmbutcher]

Hey

Looking at building an en-suite in an existing bedroom. Taking the walls back to brick. Hoping to use a toilet frame like geberit/abacus for toilet/sink but do I need to plaster/board the block wall that would be hidden behind the toilet frame Or can that remain block/brick I’m assuming that boarding it will help with condensation. I’ll be boarding the front of the frame to tile etc

 

[blup]

If its an external wall some kind of insulation gap would help, at the same time you want to be able to fix the frame to something substantial