When should gallows brackets be used?
Gallows brackets are a common solution when supporting a chimney breast during removal, but knowing when they are, and are not, appropriate is crucial for safety and compliance. Here, we guide you through when gallows brackets can be used, the structural requirements, and the legal considerations you need to be aware of.
If you need help planning your chimney breast removal project, including structural design or party wall advice, contact us here at Collier Stevens.
When do I need to use Gallows Brackets?
You may have read our article about removing a chimney breast and the requirements by law to ensure you have the correct agreements in place with your neighbour if the chimney breast is on a party wall, never mind a decent builder who understands structural concerns. What we don’t talk about much in that article are chimney support brackets, or gallow brackets, which you might need to consider once you have removed the breast, avoiding an unsupported chimney stack.
What is most important though is to make sure the remaining chimney stack is properly supported to prevent it collapsing. What you cannot do is:
- nothing;
- push a bit of timber over the ceiling joists; and
- hope for the best.
Support can be provided with steel beams under the remaining chimney (a chimney breast support beam) spanning between load bearing walls, but commonly a builder might suggest a load bearing gallows bracket.
What are gallows brackets?
Gallows brackets are triangular, right-angled units, a bit like a shelf bracket, that provide support for your remaining chimney breast or chimney stack when removing an internal chimney breast. They are used in pairs. They are made from either steel or iron and can be purchased from builders’ merchants as well as specialist companies which can supply bespoke gallows brackets. Gallows brackets will usually be welded and then fixed to the wall with resin anchored bolts and have a steel plate or metal angle spanning between them to support the chimney.
When should a gallows bracket be used?
Gallows brackets should be used when a steel beam (RSJ) is not being used. They are a crucial mechanism for chimney breast support.
Do I need a party wall agreement to use gallows brackets?
If the chimney stack is on a shared wall, a party wall agreement is generally required before fitting gallows brackets, as part of the Party Wall Act 1996 procedures.
Why use gallows brackets instead of steel beams?
Gallows brackets provide a safe, reliable way to support the remaining chimney breast or stack without the need for a full steel beam spanning the room. Brackets are fixed in pairs to a solid wall, distributing the weight and keeping the chimney stable, making them a practical alternative where a beam might be unnecessary or difficult to fit.
How do I fit a gallows bracket?
Gallows brackets are used in pairs and attached to the party wall, as shown in this picture here. (Make sure you have party wall agreement for your project, as we explained in our previous article on chimney breast removal).
Do I need a structural engineer?
Yes. As with all structural work, a structural engineer should design the brackets and fixings to ensure safety and compliance with building regulations.
When is a gallows bracket not suitable?
Chimney breast gallows brackets cannot be used if:
- They are being fixed to a wall that is less than 225mm thick.
- The projection of the breast is more than 340mm (more than 150% of the thickness of the supporting wall).
- Your neighbour next door has already removed, or partially removed, the chimney breast on their side, and has installed gallows brackets.
- The supporting wall’s brickwork or mortar is in poor condition.
Do gallows brackets require building regulations approval?
Removing a chimney breast and fixing chimney breast gallows brackets is a structural alteration and requires building regulation approval. There is some useful guidance on the LABC website.
Are timber/plastic porch gallows brackets suitable for chimney breast or stack support?
And finally, you can also get porch gallow brackets which are usually timber or plastic. Please do not mistake these for the ones you need to use for chimney breast or stack support. You can also buy ready-made brackets. Our advice is that you must get the brackets and the fixings into the wall are properly designed by a structural engineer. Do NOT let you builder cobble something together as this will nearly always be structurally inadequate.
What happens if gallows brackets are installed incorrectly?
Incorrectly installed brackets can compromise chimney support. Always follow a structural engineer’s design, and do not rely on timber, plastic, or improvised solutions.
If you need help with planning your chimney breast removal project, including party wall advice, contact us via the form below.
Steven Way
Steven Way BSc MIHEEM MFPWS MRICS is the Practice Principal and is a Chartered Building Surveyor. With over 35 years as a practicing surveyor, Steve has a wealth of experience and expertise in both residential and commercial building surveying, party wall advice and disabled access auditing. He has also built his reputation as an expert witness.