Tiling onto block work

[shabbaranks]

Hi guys

We've got a small 2m x 2m en-suite which is made up or backer board and block work rendered with a scratch coat. Can I tile directly on to the block work? I'll be using sbr for the backer board so thats fine I just wanted to check for the other walls.

Also is around 5 hours enough to leave the sbr or would you give it longer?

Cheers

 

[shabbaranks]

Wasnt sure if I asked the question correctly? The wall has a cement render scratch coat (no multi finish)

 

[tell80]

Yes, but first take up the suction.
I use SBR in two coats, first coat applied vertical, and the second coat horizontal, or vice versa - mix the second coat with water and wait for the first coat to go off.
Its off when you touch it & your finger doesn't stick.