Anyone got any experience of using the above, and can answer some
questions, please?

I'm about to lay 20no. 9 in. by 9 in. 2 in. deep old red pammets as a
superimposed hearth on which to have a multfuel stove installed (by a
professional to regs). They are going on top of a constructional
hearth that I made from concrete blocks.

To withstand heat without cracking, and for pointing, appropriate to
the tiles, I was going to follow advice received to use lime mortar
rather than cement.

Four questions -

Firstly, if I mix my own with lime putty do I use sharp sand, soft
sand or a mixture? 3-1?

Secondly, should my concreted-together concrete block sub hearth be
wetted before I start?

Thirdly, this will be indoors with central heating present - should I
take steps to stop the mortar drying out too rapidly (misting water
over the job, maybe), and for how long?

Finally, how long before it'll be ready to install a stove on it?

Thanks
Richard