If you want to remove a chimney breast in a ground or first floor room you must first support the chimney adequately. It is not enough to corbel the brickwork below the remaining chimney stack. The stack must be properly supported and the bracket detail illustrated below is one way.
Steel beams can be used instead of brackets provided that they are supported on suitable load-bearing walls.
Where a chimney stack on an external wall is partly removed, say on the end house of a terrace, the chimney stack should be reduced to be no more than 1m above the highest point of the where the stack emerges from the roof.
Where a stack forms a buttress, the wall must be checked for stability by a structural engineer. This will apply where the chimney is in a long wall without another brick wall at 90 degrees to it, other than any returning external walls. In the case of a two storey building the wall must not exceed 9m without a buttress, and in the case of a single storey building 12m.
There are 5 main requirements to consider before carrying out the work:
Updated: 20 November 2007