Floor preparation

[JMWilson]

I’ve a wet room to do with 18mm ply and a grp tray down what prep would you recommend before primers mesh & base coat?
Belt and braces and all that!
The builder is sceptical so looking for options

 

[Retired Spread]

make it up as you go along pal...seems every fker else does nowadays.

 

[BobbyJack]

Replied to your other post mate. You can do what said there alternatively if you want belt n braces I would grp the floor. Fibreglass the whole area including the tray up to the waste. Roll it up the walls a few inches too and that then eliminates any weak spots on internal wall/floor joint. On grp you don't need to prime it. Micro will key straight onto fibreglass.