Narrowing chimney opening

Hello all,

After some advice, I would like to narrow a chimney opening following the removal of the fire surround.

The opening currently has a steel lintel supported by two jambs on the right hand side the jamb leads up to a large concrete plinth where the old water tank used to sit, the side of the chimney stack comes down and sits on the lintel that is suspended across the two jambs.

I want to remove the old plinth to give us more room for the new kitchen, can I build a new jamb with some class b bricks for the old lintel to rest on and then remove the right hand side jamb and plinth and trim the lintel down?

Thanks

Its not clear what it is that you are proposing?
Can you scan a rough sketch showing how you want things to be, and where any units or work top would end up?

Hi Photo attached, I want to build a new brick stack where the red line is for the steel lintel to rest on and then remove the parts that are marked with blue lines.

Thanks,

As the upper part of the chimney breast is the part you want to keep, then you're effectively bringing the lower RH pier in to line with it. You'll need a piece of 3x2 to wedge the steel lintel up, take down the bricks within the blue lines, and then rebuild them in line with the chimney breast. Once that has been done, then you can take an angle grinder to the lintel that's been left sticking out.

OP,
What do you intend to do with a chimney breast that will be approx. 36" wide with a 18" x 48" opening?

I'd suggest that you build up the RH side (jamb) to support the steel lintel, and only later to remove any more masonry, and cut the lintel to suit.

FWIW: there are a couple of soot damaged bricks used to in-fill on the RH corner of the c/breast.
Remove them and replace with clean brick.