Hi, I'm about to fit a cast iron fireplace into a chimney breast which originally was used for that purpose so the dimensions seem ok. I've bought a secondhand reproduction cast iron fireplace (one with tiled insert) and a seperate wooden surround. To fit, do I simply place the metal insert into the opening and place the wooden surround over it and screw the surround to the wall? Or do I actually need to chip away some of the plaster and set the edges of the cast iron insert back a fraction in the wall and plaster in place? I've read of people using fire rope to stop smoke escaping through the sides, but I'm not sure if this is required. I realise I will have to backfill with rubble and mortar and top off with fire cement but I'm just not sure what exactly secures the insert in place if you know what I mean?
The fireplace will be used occasionally to burn solid fuel. The chimney has been cleaned and checked.