Removal of a Chimney Breast

[andystudent]

All,

I am trying to research what the structural risks are associated with the removal of a chimney breast from the ground floor.

The building is detached and the breast is constructed of 115mm standard bricks. I am assuming that the removal will leave the external cavity wall with a risk of buckling deformation, bending deformation and possibly tension deformation.

Would it also be right to say that their is a risk of shear deformation of the ceiling as the weight of the chimney still exists above the ground floor level.

Any help will be appreciated on this, Many Thanks Andy.

 

[Shytalkz]

Blimey, have you swallowed the ladybird book of basic structural bending theory?

The answer is very little, providing that the temporary support arrangement is adequate and the support arrangement to the stack and floor/s above is similarly so.

 

[^woody^]

The main risks wont be in any text book - and that is when constructing the the chimney the internal bricks to the flue and whiffs will have just been thrown in, and together with the cement being attacked by the flue gas, this leads to a potentialy unstable remaing wall with soft crumbly mortar.

This will increase the potential for buckling/bending, when combinded with the load from the stack above if canterlevered or supported off gallows brackets

If the remaining parts of the stack are supported off a beam or two spanning from adjacent walls, then it will aid stability of the wall

Ceilings and floors should never go into a stack, and are trimed around it so there are no loading issues there

 

[Shytalkz]

...supported off gallows brackets

Yak, not good, especially in old walls. And nigh on impossible to prove by calculation, at least to the satisfaction of the LA engineer, a species which we all know are totally hidebound by intransigence and a wholly prescriptive approach to structural matters.

 

[^woody^]

There is an LABC guidance note which details bracket design/size etc which should be acceptable for all LA's without further calculation. But yes, getting a good fixing into an old wall may be a problem

 

[Shytalkz]

There is an LABC guidance note which details bracket design/size etc ...

Well, I never knew that, got a linky?

 

[fastneattrowel]

All,

I am trying to research what the structural risks are associated with the removal of a chimney breast from the ground floor.

The building is detached and the breast is constructed of 115mm standard bricks. I am assuming that the removal will leave the external cavity wall with a risk of buckling deformation, bending deformation and possibly tension deformation.

Would it also be right to say that their is a risk of shear deformation of the ceiling as the weight of the chimney still exists above the ground floor level.

Any help will be appreciated on this, Many Thanks Andy.

andy wouldnt it be wise if possible to take the whole stack down through the roof ect,where is the stack placed on the roof end side middle ?

 

[Shytalkz]

Effenntee, I think it's a college project he's been set...

 

[fastneattrowel]

Effenntee, I think it's a college project he's been set...

duh me i think your right lol

 

[^woody^]

There is an LABC guidance note which details bracket design/size etc ...

Well, I never knew that, got a linky?

Try this

Brent Council

 

[Shytalkz]

Hmmm, no mention of max height of stack that can be supported, nothing about checking the condition of the masonry, can't get that size of angle any more, either. Moving the bottom bolt down and the upper one up would increase the lever arm and reduce the pull out load on the top bolt.

The danger of a one-size-fits-all detail

 

[^woody^]

Who cares as long as it passes BC, and saves £200 engineers fee. lol

 

[Shytalkz]

Oi