Steel design to support chimney stack Loft Conversion

[Roger Mcormack]

Hi All,

Builders are in the process of starting a loft conversion for me. My neighbour is still using one of his flus in the chimney so there is not an option of removing the chimney stack. A SE has suggested that he can support the stack with a beam which will allow me to remove the chimney breast at loft level. He showed me some pics.

Is this a valid and safe design? Will appreciate your comments.

 

[tony1851]

I think we get the message....!

 

[Roger Mcormack]

Apologies, photos ended up getting uploaded twice.

 

[tony1851]

Looks perfectly sound, incidentally, in fact perhaps a little over the top.
One central post would have sufficed.

 

[^woody^]

Whilst technically it may well be able to be proved by an SE, I would not want a steel beam in such an important, but exposed and vulnerable location unless it was galvanised.

And exactly how much extra room has been gained after all this malarkey and expense?

 

[Roger Mcormack]

Looks perfectly sound, incidentally, in fact perhaps a little over the top.
One central post would have sufficed.

Thank you for your response

 

[Roger Mcormack]

Whilst technically it may well be able to be proved by an SE, I would not want a steel beam in such an important, but exposed and vulnerable location unless it was galvanised.

And exactly how much extra room has been gained after all this malarkey and expense?

Hi Woody,

How much chimney breast is permitted to be removed in the loft if I did not go for this option? As I want to remove as much as possible to maximise space

 

[cdbe]

Looks like it gains half a brick!!

Can't you rebuild the stack on your side a bit narrower with it still being structurally stable? I've seen many rows of houses with back to back stacks and half width single stacks on the ends.

 

[Deluks]

If the engineer says it ok then it's ok.

As per previous replies, it's a bit OTT for a few extra feet of space. Much (much) cheaper to just plasterboard around the existing breast. You can still use the space either side for alcove shelving or cupboards.

Also, if at any point in the future someone wanted to reinstate the chimney to install a woodburning stove (for example), then it would cost a lot more without an existing flue, and be more disruptive internally.

 

[^woody^]

Hi Woody,

How much chimney breast is permitted to be removed in the loft if I did not go for this option? As I want to remove as much as possible to maximise space

There are several factors that will influence this so its not a straightforward answer.

You need to be clear of the advantages compared to the cost and end result. Any engineer could design you something and would love to do that and be paid handsomely, and likewise any builder will just do what is asked of them and be paid for it. And building control will just agree any engineers design.

Also be aware of the Party Wall Act, the costs in that and the potential for the PW surveyor to require different or additional works - all at your cost too.

That design in the photos looks to be a complete waste of time and money for removing 230mm of what is already a large loft area.