Removing a chimney breast reclaims space in older homes but introduces a structural challenge: everything above it still needs to be supported. Done wrong, it is one of the most common causes of partial roof collapse.
What you're actually removing
A chimney is a stack of brickwork rising from the foundation through every floor to the roof. Removing it on one floor leaves the stack above unsupported — that part has to be carried by new steelwork.
Common removal scenarios
Ground floor only
Most common. The flue and brickwork on first floor and in the roof must be supported. Standard solution: two parallel steel beams (gallows brackets or full beam pair) at first-floor level transferring load to walls either side.
First floor only ("middle removal")
Less common. The chimney above (in roof) must be supported. Possible but requires careful detailing.
Roof level (chimney stack)
Stack above roof line removed. Roof rebuilt to seal. Simplest structurally.
Full removal (all floors)
Demolition top-down. No supporting structure needed once gone.
Costs
- Ground floor breast only (with steelwork): R50,000–R110,000
- Two-storey removal: R80,000–R160,000
- Full removal (top to bottom): R80,000–R180,000
- Structural design fee: R10,000–R18,000
Party wall considerations
Many chimney breasts are on party walls between terraced or semi-detached houses. Removal requires:
- Party Wall notice to your neighbour
- Possibly a Neighbour Support Agreement
- Notification of any disturbance to their flues
Building Regulations
- Structural calculations submitted
- Fire compartmentation maintained (sealed flue openings)
- Any retained flues must still vent properly
What goes wrong
- Removal without support — stack above sags and cracks ceilings
- Inadequate gallows brackets — chimney migrates over time
- Failure to seal flue — water ingress through roof
- Neighbours' chimney destabilised — party wall dispute
MCFAR designs chimney breast removals across South Africa.
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MCFAR GROUP has been delivering structural engineering, building, and plumbing services since 1998. Talk to our team about your build, retrofit, or renovation.
Request a QuoteFrequently Asked Questions
Can I leave the chimney stack on the roof if I remove the breast inside?
Yes — most common arrangement. The stack is then supported on steelwork in the loft.
Do I need building regs to remove a chimney breast?
Yes. Structural calculations and inspection are required.