Tile Adhesive for Shower Base?

[A and E]

Hello,I owuld appreciate some advice on using tile adhesive for a shower base. The base is to go onto a raised platform of which the top level is backer board (see photo). I've tried using a standard mortar but have had a bit of a mare, so the base had to come up again.

One tradesman suggested using tile adhesive to set the base onto. I used adhesive for 'mconstruting' the platform, but was wondering if anyone as any experience or opinions on using it in place of mortar to set a base into?

Many thanks,

 

[foxhole]

What’s wrong with mortar base?
What’s base made of?

 

[A and E]

It's a stone resin base. The mortar wasn't adhering very well to the base and the base moved on the mortar after it had dried.

Thanks

 

[foxhole]

Just needs a wetter mix.

 

[A and E]

Thanks for your comment. Is there any reason not to use tile adhesive? I used adhesive to make the rest of the platform (see photos) and it has served well. The raised base is over an underfloor heated floor too.

Cheers again.