Knocking out ground floor chimney breast

[thias]

I want to knock out the chimney breast, just in the ground floor room, leaving the second floor breast and the stack above. I also want any support to be hidden within the floor void.

The room is approx 4.5m wide, the external wall on one side is 320mm thick and the internal wall on the other side is 215mm thick. The first floor joists above run parallel to the breast.

I assume I’d need to support the breast above with a number of acrows whilst I fit an RSJ, resting into the walls at either side.

Does that sound right? Structural engineer to perform the RSJ calcs, of course.

 

[Wayners]

Ask a structural engineer. They will give you a spec to work to

 

[^woody^]

Gallows
Building Control
Party wall Act?

An engineer is not necessarily required.

 

[thias]

Gallows
Building Control
Party wall Act?

An engineer is not necessarily required.

Detached house so party wall won’t be applicable. I was of the understanding that gallow brackets are no longer recommended. They’d be much easier…

 

[tell80]

OP,
Are you saying that the c/breast in question is backing onto an external wall or an internal wall?
Gallows brackets wont fly if you want to conceal the c/b support in the first floor void.
Gallows brackets are nowadays frowned upon by BCO's even when used in a loft.
Depending on the age of the property, the parallel joists should still trim the c/b in the first floor void,
older properties sometimes have the "trimming" supported by the c/breast brickwork.

Why dont you post pics of the ground floor chimney breast - and the first floor c/breast at hearth level.
Plus pics showing the external wall if the c/b is on an external wall, & the roof c/stack?

 

[George_engineer]

Gallows are only suitable if you've got a thick wall or a neighbour's chimney stack to bolt into (see link below for more details / limitations). They've gone out of favour because if in a semi-detached/terrace the neighbor also removes their chimney you've got a lot of weight held up by a thin bit of wall.

How to get it right: Removing a chimney the right way (with video showing the wrong way...) | LABC

One of the most common internal alterations carried out is to remove an obsolete chimney breast at ground floor to create more floor space. Quite often the chimney is also removed at first floor level leaving just the roof void and external section of the chimney in place. Building Regulations...

www.labc.co.uk