Hi guys - my first post here. I'm tiling my entire bathroom - floor to ceiling with 12mm travertine (60x30cm) The walls are a mix of solid granite with lath & plaster (mixture of sound and unsound), stud plaster board and plastered breeze block. My intention is to batten onto the existing surfaces (plastered stone & block walls) using 32x32mm battens and fit aquapanel ready for tiling. (Stripping the plaster back to the bare stone would be a nightmare and 80% of the wall is a sound finish) For the PB walls I'll replace the PB with aquapanel as I read on here that aquapanel can take the weight of these tiles. Is this a reasonable approach? Is there a cheaper or easier way of doing this? (I have assumed I can't tile directly onto the plastered walls in shower/bath area hence batten/aquapanel) Have I missed anything obvious? Thanks in advance!