Chimney breast anatomy & opening

[plumsnson]

Hi all,
I'm planning to open a larger opening in this chimney breast, in order to install a direct air supplied stove, insulate & seal the flue liner, block any other draughts in to the room.
(Background: retrofitting airtightness and insulation to a small 1926 house)

I think it will be OK to use a few accrows in above, supported on a board across the hearth, to install a lintel as shown in red, then knock out the brickwork inside in red, back to the party wall, then line it. Am I missing something important?


I wanted to know if the appearance of the brickwork suggests the history of it's construction and alteration?
It had a small gas fire installed in the present opening, which has a metal lintel and an untidy rubble fireback.
A neighbour says it used to have an open fire with back boiler.

The brickwork face is far from flat and looks discontinuous, I think there's some kind of infill in yellow, a patch in green (is this from construction of the chimney throat?), a step in the face at the blue line (why??) and some brackets left in nooks in red (for what?).

Brackets:


Diagonal view

 

[23vc]

It’s been messed about with a fair bit over the years. Yes, use one or two acros. Often you don’t need to and can get away with just cutting the lintel in but in your case, that whole section that’s obviously been added later (green in your pic), is likely to drop, so yeah, prop it.