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.
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:
- a) nothing;
- b) push a bit of timber over the ceiling joists; and
- c) 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.
How do I fit a gallows bracket?
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.
Not to be mistaken with…
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.
If you need help with planning your chimney breast removal project, including party wall advice, contact us via the form below.