Opinion on blocking up small flue

[Flinstone]

We have a room which was once a kitchen but has since been knocked through into the dining room (ie now one large room the width of the house).

Following the replacement of the window on what was once the kitchen wall, I am now moving on to replaster the whole wall. In doing so I thought I would investigate why one corner of the room was 'boxed in' at 45 degs in the hope I could gain a little more practical room space.

Having removed the plasterboard I find what must have been a small kitchen flue about 6" internally across. The house is of single wall construction.

View of corner of room with plasterboard removed (a small number of bricks removed):-
http://i122.photobucket.com/albums/o266/HumphreyLittle/complete.jpg

Closeup view looking up toward flue. Flue is approx 6" square:-
http://i122.photobucket.com/albums/o266/HumphreyLittle/closeup.jpg

The second-storey bedroom directly above it has no such brickwork, so the flue seems limited to the ground floor (perhaps the upper floor brickwork was altered some time earlier?). My main concern is if I remove the brickwork which runs at an angle, will it risk the structural integrity of the house? I'm thinking more about the lateral strength it might be giving between the two external side and original back walls (the replacement single-storey kitchen is now annexed to the back wall).

Is it okay to remove the brickwork angled across the front of the flue and replace with, say thermal block (assuming simpler to cut into awkward shapes)?

Thanks for your opinions!
Flinstone

 

[noseall]

removing the brick work isn't likely to cause any structural problems. the sooted bricks however will.

before plastering remove as much of the soot as possible from the brick's surface. you will then need to do an s.b.r. render to the affected masonry.

instructions are on the 5 litre bottle.

 

[Flinstone]

Thanks noseall,

I'm not sure whether the closuep.jpg piccy in my first post helps much but it was meant to highlight that if the diagonal-facing brickwork were to be removed, there would seem that only half the wall thickness is left to join the corner of the house, downstairs at least! Likewise the bricks with the soot on them would not be near the finished plaster level.

Hence my concern whether the bricks intended to be removed are actually aiding the tieing of the walls together in a more significant way than I first thought

 

[ModernMaterials]

Brick it back up to a state you are happy with before you plaster.

 

[Flinstone]

Are the lightweight blocks like these just as good as a replacement for house bricks?
I'm wondering which is the most convenient to use in order to best fit the void.

Cheers

 

[Lower]

removing the brick work isn't likely to cause any structural problems. the sooted bricks however will.

before plastering remove as much of the soot as possible from the brick's surface. you will then need to do an s.b.r. render to the affected masonry.

instructions are on the 5 litre bottle.

without hijacking this post, what is the issue with soot and plaster? I presume that there will be a staining issue, or is it an adhesion issue? We just had the inside of a fireplace plasterboarded and then skimmed, hence my interest.

 

[noseall]

brown stains can occur on the surface of the plaster and is strong enough to discolour paint.