Gallows Brackets vs. Steel Beam (RSJ): Which is Best for Chimney Removal?
Removing a chimney breast is a popular renovation for creating more space, but choosing the correct structural support for the remaining chimney stack is crucial. The choice often comes down to two methods: Gallows Brackets or a Steel Beam (RSJ). We explain the difference, the risk factors, and which solution your local Building Control is most likely to approve.
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Email Plans for a Fixed-Price QuoteThe Technical Comparison
⚠️ Gallows Brackets
- What they are: Two angled metal brackets fixed to the chimney stack wall below the removal point.
- Load Distribution: Transfers the weight of the chimney above directly to the wall below, creating concentrated stress points.
- Safety Risk: Can be structurally inadequate if the masonry is poor or the remaining stack is too heavy/tall.
- Building Control View: Rarely accepted by local councils due to inherent risk, particularly in mid-terrace houses or above the ground floor.
✅ Steel Beam (RSJ)
- What it is: A horizontal Rolled Steel Joist (RSJ) or universal beam/column (UC/UB) inserted into the wall.
- Load Distribution: Distributes the load evenly across the entire width of the supporting wall (via padstones).
- Safety Assurance: Provides a robust, calculated, and predictable support solution based on modern Eurocodes.
- Building Control View: The universally accepted and preferred method, provided a certified Structural Calculation Report is submitted.
🏆The Verdict: Which Method Should You Choose?
From a modern structural engineering perspective, the Steel Beam (RSJ) solution is superior in nearly every scenario, and we strongly recommend it. Gallows brackets were a common, older method but are now considered an unsafe and unpredictable solution for most domestic chimney breast removals.
Key reasons to choose a Steel Beam (RSJ):
- Guaranteed Support: An RSJ is calculated precisely to bear the exact load of the remaining masonry.
- Even Load Transfer: The beam safely transfers the chimney weight horizontally before directing it vertically through robust padstones to the ground.
- Future Safety: Prevents settlement, cracking, or the devastating possibility of collapse into the void below.
🏛 What Local Building Control Will Approve
For any chimney breast removal, your local council (e.g., Dartford Borough Council or Bexley Council) requires you to submit a Building Notice or Full Plans Application to demonstrate compliance with Part A (Structure) of the Building Regulations.
While historic exceptions exist, most modern local authority Building Control departments will only approve a chimney breast removal if it is supported by a properly specified and calculated Steel Beam (RSJ).
To secure approval quickly and avoid project delays, you must provide:
- A certified Structural Calculation Report signed by a qualified engineer.
- Detailed Construction Drawings showing the beam type, size, position, and padstone specification.
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