Hi,

Any thoughts, ideas, advice are appreciated.

I have a homemade/handmade fireplace (real chimney behind it as once
there was an open fire).

I have decided to remove the old valor external gas fire and replace it
with an inset Kinder (glass fronted if it matters). My problem is the
opening where the fire has to go through is bigger (both height and
width) than the fire (and for this matter any gas fires I have found).

That is, the existing opening is
width = 460mm
height = 600mm

Gas fire based on its flange needs
Width maximum = 450mm
Height maximum = 570mm

All I can think so far is to create a stainless steel flange (two sides
plus the top) and put on the back of the fireplace and create a smaller
opening. Is it a likely solution? (Waiting for a heating engineer to
come next week).

How solidly would it have to be placed on the fireplace glued?
screwed/bolted? (I might as well break the back plate of the fireplace
and be done with it).

How do inset fires get placed in the opening so they are sealed for
gases escaping back in the room? (normal chimney).

TIA
Charles

PS. I do not intend to fit the gas fire myself, but I have so little
feedback from the supplier/fitter company that it gives me the
impression they are not interested.

PPS. A wide flange would not be an aesthetic issue as it would be bigger
than the surround of the gas fire ... fire and flange would be steel.