Rendered wall residue

[besenzig]

Hi

I am tiling over a rendered wall which was previously tiled using the Ready mixed adhesive.

I have removed all the old adhesive to give a smooth finish but it has left some residue in between
the grains of sand/cement. As its powdery I was intending to prime this with Mapei primer G diluted 1:1
and then tank the wall using the Mapei shower kit.

Am I doing the right thing, just concerned about this ready mixed residue and whether the Mapei product will
adhere properly.

I have even used a wire brush on a drill to get it off, its as clean as I can get it.

Any advice woulf be appreciated.
Thanks
Julian

 

[White Room]

I would prime as it's an old rendered wall.....

 

[Dan]

Does it definitely go over render the shower kit?

 

[besenzig]

Dan

The Mapei Technical guys advised I use the shower kit (tank) even though its a rendered wall. They would not
comitt themselves to the ready mixed adhesive residue on the render. Just wondered if anyone
has come across this and what they did.

 

[Ian]

How much residue are we talking? As a percentage, roughly.

 

[besenzig]

How much residue are we talking? As a percentage, roughly.

Probably about 75%...