Tollerances/out out plumb walls etc

[Guitardedleon]

Generally what is acceptable tolerances for walls when preparing to tile?For instance my Bathroom in a house we are renovating to move into is very very small at 2.5x2m - x2.4m floor to ceiling.On one of the 2m walls under a window the wall has a bowl going horizontally - the centre of the wall being about 11mm in compared to the sides. ( I've attached some photos to give an idea of the walls )The rest of the walls are out by 5-7mm here and there but generally pretty plumb and true.so, what would you suggest with regards to prep before we tile to get as good a finish as possible?Pics:

 

[Ian]

You won't get a true reflection of what the walls are like until you remove the existing tiles. Your wall may be a lot better than you think, it could be the tiles that are poorly fitted. To answer your question, you don't want I have variances of more than 5mm over a 2 metre wall.

 

[Guitardedleon]

only the one wall is tiled, the rest are just plaster including the one with the 11mm difference

with that in mind, how would you rectify the unevenness?

Thanks!

 

[AliGage]

Is it render and skim? How old is the property?

 

[Guitardedleon]

Is it render and skim? How old is the property?

Property is approx 60 years old
prefab construction , poured concrete.
then hard-wall with unbelievable amounts of plaster. being ex council the plasterers have literally skimmed around the bath and toilet more than once, literally sinking them into the walls - same goes for skirting boards being behind the plaster level! absolutely shocking state

I dread to think what I am going to find when I rip it all out!

as a side note: my posts don't paragraph or separate the way I type them in, any ideas as to why?
else it just appears as a wall of text

 

[White Room]

Property is approx 60 years old
prefab construction , poured concrete.
then hard-wall with unbelievable amounts of plaster. being ex council the plasterers have literally skimmed around the bath and toilet more than once, literally sinking them into the walls - same goes for skirting boards being behind the plaster level! absolutely shocking state

I dread to think what I am going to find when I rip it all out!

as a side note: my posts don't paragraph or separate the way I type them in, any ideas as to why?
else it just appears as a wall of text

Has the walls been redone since the place was built...

 

[Guitardedleon]

No idea to be fair whitebeam
it may not be hard-wall, But its certainly not plasterboarded walls, but I do know its a poured concrete construction

I dont live at the property so would need to take a better look
but a previous tiler has obviously had issues with the wall hence the lip seen in photo 1

 

[AliGage]

Might be an idea to get a plasterer in to take a look at what can be done.

 

[Guitardedleon]

Probably right there
and considering the sanitary ware has been kept in place during the multiple reskims, it probably isn't going to be suitable once ripped out and exposed.

 

[Guitardedleon]

had a plasterer take a look this morning and have 3 more due to look tomorrow

the one Today wants to use hardwall to bring it all flat and to leave that as the surface to be tiled
as far as I was aware you can not tile on hardwall or other BG backing coats?
so a bit cautious to hire him, especially since he hasn't quoted yet until he can see how it looks once the suite is out.