replying to Christian McArdle, Tom wrote:
Im a bathroom fitter. Ply, no matter the quality expands and contracts with
temperature change and will cause grout to crack. Moisture resistant
plasterboard or tile backer board doesnt and is cheaper, marine ply is
something handymen fit thinking there doing the right thing, but Ive lost
count of how many insurance jobs Ive done removing it.
--
for full context, visit
https://www.homeownershub.com/uk-diy...es-176228-.htm