Advice on adhesive

[Ehhh]

HI,
Just about to tile my en suite out. The walls were half tiled splash back and fully tiled in the shower area. I've stripped them off and scrapped the wall down, 16m2.
Just after advice on primer, adhesive and notch size for ceramic tiles 400x250 with a mosaic border running around the room.
The walls are okay with skimmed plaster and bare plasterboard in the shower area.

 

[Dan]

Prime with an acrylic primer and use a cement based adhesive to tile with. I'd also seriously consider tanking the shower area with a waterproof tanking kit which ensures you never damage the background when water runs behind the tiles (which it will).

Cement-based grout then too. Silicone around the shower and in internal corners.

 

[Ehhh]

Thanks Dan.

Just wondering about notch trowel size for the tiles and also the mosaic border. I was thinking 10mm for the tiles and also 4mm for the mosaic?

Also would it be best to scratch up the painted areas and prime?

One last question, would mapei keraflex be a good adhesive for the full job, shower and normal walls?

Thanks in advance.