Cast Fire Surround

[ppgflyer]

Hi this is my first post so please be easy on me.....
I am in the middle of fitting an open fire, I have bought a Agnews cast fire back.
My question is when I fit the fire insert onto the wall, should I sit the legs directly onto the granite hearth and should sit them on some fire rope to allow for any contraction and not to put any direct pressure on the hearth.
Thanks in advance Paul Smith

 

[Nige F]

Is that the Spiro T model wouldn`t hurt to use the rope also any back fill wants to be weak sand cement with lime mix.