Home › Steel Beams For › Steel Beams for Chimney Breast Removal
Steel Beams for Chimney Breast Removal
Taking out a chimney breast is straightforward. Holding up the several tonnes of masonry left above it is the part that needs steel.
Get your steel priced
Send us your engineer’s drawings and we’ll work out quantities and price the steel and the processing together — cut, drilled and finished to your specification, delivered direct to site.
The problem is what stays, not what goes
A chimney breast is rarely removed all the way up. In most houses the ground floor breast comes out to reclaim the room, and the breast on the floor above, the stack in the loft and the pot on the roof all stay exactly where they are. That masonry is heavy — a remaining upper breast and stack can run to several tonnes — and it has to be supported on whatever replaces the breast below it.
This is the single most common reason chimney breast work goes wrong. The removal is easy. The support is a structural design problem, and it is not optional.
Beam or gallows brackets
There are two usual solutions. Gallows brackets are steel brackets fixed into the chimney breast masonry either side, cantilevering out to carry the remaining breast above. They are neat and avoid a beam across the room, but they depend entirely on the condition and thickness of the masonry they are bolted to, and many engineers and building control officers will not accept them where the brickwork is poor or the load is high.
The alternative is a beam spanning the opening left behind, bearing onto padstones at each side, carrying the breast above in the normal way. It is the more robust answer and the one usually specified where the loads are significant or the masonry is not up to bracket fixings. Which you get is the engineer’s call, not a preference.
Two things people forget
The first is the party wall. In a terraced or semi-detached house the stack is very often shared, and work to a shared chimney breast is notifiable under the Party Wall Act. That is a legal process with notice periods, and it runs in parallel with Building Regulations rather than instead of it.
The second is that removing at one level changes what the levels above are doing. If you take out the ground floor breast now and the first floor breast later, the support designed for the first job may not suit the second. Tell your engineer the whole plan, not just this phase.
Typical sizes for this job
Chimney breast openings are usually narrow, so the sections are typically at the lighter end — but the load per metre can be high because masonry is dense.
| Size | Weight | Indicative Span | Typically Used For |
|---|---|---|---|
| 127 x 76 x 13 | 13 kg/m | 2–2.5m | Narrow openings with a modest breast above |
| 152 x 89 x 16 | 16 kg/m | 2.5–3.2m | The common answer for a standard breast opening |
| 178 x 102 x 19 | 19 kg/m | 3–3.5m | Wider breasts, or where more of the stack remains |
| 203 x 133 x 25 | 25 kg/m | 3.8–4.5m | Heavier loads, or where the opening is being widened at the same time |
What else the steel will need
Most beams need more than cutting to length before they reach site. All of it is arranged on the same order:
- Cut to size
- Painting, priming and intumescent coating
- Welded cleats, end plates and connections
- All processing and fabrication services
Related jobs
Common questions
Can I just use gallows brackets?
Only if your engineer and building control accept them. They depend on the condition and thickness of the masonry they fix into, and are commonly refused where the brickwork is poor or the remaining load is high.
Do I need Building Regulations approval?
Yes. Removing a chimney breast and supporting what remains is structural work and requires approval with signed calculations.
What about the party wall?
If the stack is shared with a neighbour — usual in terraced and semi-detached houses — the work is notifiable under the Party Wall Act. That runs alongside Building Regulations, not instead of it.
Why is the beam so small for such a heavy load?
Chimney openings are narrow, and span drives bending far more than load does. A short span under a heavy load can still need only a modest section, though the bearings and padstones matter a great deal.
Ready for a price?
Send your drawings or a cutting list and we’ll come back with quantities and a price. Large and small orders both welcome.
We supply structural steel across London, the South and the Midlands, delivered direct to site. Information on this page is general guidance; the specification for your project must come from your structural engineer.
Major credit cards accepted
Call UsSend us your plans!
Send us your building plans and let us give you a quote. Upload plans
delivery to site