limestone slab to cemfloor, cement or tile adhesive bed?

[Barryscotland]

Using black limestone slabs to form a hearth on top of cemfloor, anybody no if I should use cement or tile adhesive to bed? If cement do I still need to prime the cemfloor?

 

Thanks

[markc]

Either will be fine, you don’t need a hearth to ‘stick’ anyway so it’s just a bedding layer

[jayc89]

Pretty sure our tiler used adhesive.