Supporting chimney stack on hipped roof

[thias]

Detached house, hipped roof. I want to remove the chimney breasts in the ground/first floor rooms as they're no longer used and just take up space. However I'd like to retain the stacks on the roof, as a feature of the property (built around 1880)

Pretty straight forward on a gable end, however on a hipped roof, the stack isn't tied in above the wall plate so would just be balancing on any steelwork. Roof joists runs parallel to the stacks at approx 400mm centres. 2x king post trusses which, I'm told, distribute the load to the external walls, so no internal load bearing walls either.

Is there a tried and tested method of doing this on a hipped roof?

I would be getting a structural engineer to provide any calcs, I just want to be sure I'm not walking into a very expensive job before I instruct them.

 

[RonnyRaygun]

I’d remove the chimney In its entirety and replace with a GRP one with brick slips or similar

 

[thias]

I’d remove the chimney In its entirety and replace with a GRP one with brick slips or similar

It's not really an option. The house is 150+ years old so brick slips will stick out like a sore thumb.

Interestingly, it's just occurred to me that the stack dog-legs out half way up the first floor room, so there's not much brickwork that could be tied in to support the stack above the roof, so I don't know how it's currently supported - it presumably is, and pretty well, given its age...

 

[^woody^]

You get brick slips cut from 150 year old bricks (the ones fron the existing stack) and pointed in 150 year old style, then it blends in not stands out.