tiling onto slate - Tile Advice

[lauratryinghard]

hello from a new member : ) hope to listen and learn much from you all.
I have a slate tile laid in concrete in a wetroom which is solid as f*** and really dont want to have to break it up. I want to tile over it. Possibly you will all tell me i should listen and learn, but maybe someone has an idea. I have tried and failed once already.
What suggestions to prep the tile to tile over? probably will use a small ceramic tile this time. its a little uneven and slight slope down to a long drainage channel. Its an outdoor bathroom on a camping site so gets a fair bit of traffic and i need it to be solid. I can afford the height but will need a solution also for the edge where it falls down to the drainage channel (stubbed toes etc.!)
Eternally grateful for any tips to prep the slate!!

 

[Dumbo]

We need picture of the drainage channel .
But thorouly clean your existing tiles with good quality tile cleaners from a company like lithofin to remove any soap scum or sealers used during installation, then smooth over using an exterior grade levelling compound such as ardex k301 or tilemaster exterior levelling compound then tile over .
I would recommend porcelain rather than ceramic in an exterior instal

 

[Glynn]

And prime the tiles with Prime&Grip.

 

[J Sid]

And prime the tiles with Prime&Grip.

Other primers available, 🙄😂

 

[Glynn]

But are they as good?