Opening up a chimney breast

[badbuilder]

I have a late 1890s mid-terrace 2 up 2 down, at the rear is a chimney stack. The rear stack has already been removed to below roof level (and the roof repaired badly). The stack is still in the loft, the rear purlin rests on the stack. There is a chimney breast in the bathroom below and the lounge below that. The stack is not shared with the neighbour.

The original plan was to remove the lot from the ground to the roof, but budget put paid to that with the purlin supported by the stack.

Since my objective is to put the kitchen into the lounge where the chimney breast is, I'd like to open up the chimney breast in the lounge (rather than remove it). It is 1750mm wide (including the plaster) and 370mm deep. The ceiling is 3m high. The chimney breast in the bathroom is less wide than that below it.

I happen to have a spare unused concrete lintel lying around, 1.8m long, 100mm x 140mm thick.

Would it work to trim the lintel a little shorter and remove the face of the chimney breast up to 2m high, keeping it up with a strongboy acrow, in order to place the lintel in at the 2m height, resting on a minimum of 150mm of width at either side?

There would be a gas hob and extractor fan under it all, with the extractor returning air to the room rather than up the chimney.

Maybe useful information - two of the joists of of the bathroom floor above it sit in cutouts in the chimney breast. My plan would be to add noggins to help spread the load into other joists. The joists span 4.1 meters to the other wall.

Thanks.

 

[Doggit]

I think you've worked out to do quite nicely, but as you're putting in the lintel, I don't think you need to add the noggings.