UK Ready mixed adhesive with 60x30 tiles - will it set?

[Stoobloo]

Is the issue with ready mixed adhesive seemingly only recommended for 30x30 tiles max that it will not set at all giving required adhesion, or is it that it will take a longer (than the usual 24 hour) setting time?

 

[Dan]

It dries by dispersing the water contents and it can't do that behind a big tile. You could end up sealing it behind and it never setting, like in a tub.

So cement based only.

 

[Dave]

Also depends what your background is. ?