u/Hackerssuck3

Hi all,

My shower has been leaking for a while, I put loads of fresh silicon around everywhere, called a plumber and added fresh grouting.

I noticed there was mould behind the shower so figured water was coming through the wall.

I removed a few tiles and found this behind, very crumbly plaster and lots of mould.

Id really appreciate any advice for how I could begin to fix this?

Many thanks!