Leveling wall with tile adhesive

[moomarine]

Got a job next week with one wall having a fair convex bow in the middle-ish of the wall. Usually I would level/feather with rapid cement based tile adhesive using my feather edge etc but the question is - what is the max depth per layer when leveling using rapid set? Am I correct in thinking it's about 12mm?

Also I have been told that another good way to deal with the really low parts is to use notched side of trowel, let set then go over again with straight edge.

Just interested to know how all of you deal with leveling using addy if you do atal? Obviously would be nice if wall was level from the start!

 

[Time's Ran Out]

What's the walls construction?

 

[moomarine]

The wall in question is a solid plastered wall but there is also a wall in this room which is 12mm hardiebacker which is also not level!?! - as in one board is not square above the board below if you know what I mean? So it sticks out probably by a couple mm! Non of this prior work was done by me btw

 

[SJPurdy]

Consider the weight of the layer of adhesive/render you are adding to the plaster wall. The weight of this plus the normal fixing layer and the tiles with grout should not exceed 20kg/m2.
Adhesive max thicknesses stated by manufacturers are for a bed under a tile and are limited by the shrinkage stresses amongst the things. I suggest you check with each manufacturer if wanting to use as an expensive render. If it's that bad i'd consider reboarding/overboarding it.