putting in a fireplace

[vernerbongo2]

Hi guys,
Bought a second hand fireplace.

Currently there is no fire back in the chimney opening.
The fireplace inset is cast iron with a cast iron back.

I've been told I can put it in without filling it up behind but someone else reckons I still have to fill it up at the back?

The previous owner said there was nothing behind it when it was taken out.

Also what's the best way to seal it around the inset?

 

[stuart45]

If you are going to use it as an open fire it's best to fill the back in with a vermiculite/cement mix. Years ago it was rubble/lime mortar.

 

[dann09]

As stuart said, it's best practice to insulate but not a must.

Fire rope seal and, perhaps, some fire cement were traditional.

 

[vernerbongo2]

Anybody else want to give a bit of input?