twin wall to extend masonry chimney?

[Simon F]

For a log burner, I know it is possible to use twin wall flue to carry on from a brick chimney that has been shortened to below the roof. A plate/adapter to fix to the masonry and go from flexi liner to twin wall then through the roof.
Flue liner adapter plate (6 inch) - Twin wall flue - Twin wall flue systems (Black) 6 inch (150mm) t

My question is, can it be done on a chimney that has been lowered but is still above roof level?
the only info I can find is for where the brick chimney is truncated below the roofline.
If it can be done what would be used to cover the plate, flaunched??

 

[lame plumber]

Personally I would build the chimney back up it will look better and last longer.

 

[Simon F]

I agree, the issue is that it would need to go up a fair way.
the roof pitch is about 45 degree, the shortest dimension on the chimney is 460 mm.
times it by 4.5 comes short of 2300mm.
The chimney is on the external wall and would be much simpler if what was first asking is acceptable.

 

[lame plumber]

I know what I would do, dont know bout your idea I.m afraid as it wouldnt feature in my plans.

 

[Ermintrude]

I would say no not ideally. Can't you square it off and fit an 18" tall pot with a hanger for the liner?

Just read 2300m short comment. A twin wall would need some serious support and the steel work would probably be more than masonry!

 

[Simon F]

to hit the magic 2300mm to the roof, the existing chimney will need to go up by about the same because of the pitch,
currently is only 6 courses (500mm)from intersection.

 

[Ermintrude]

Needs a builder then.