Gallows Brackets Supporting a Chimney: What You Need to Know

When it comes to property renovations or structural alterations, especially in older buildings, understanding the proper support for remaining structures is crucial. One such element commonly encountered in UK homes is the chimney breast. Removing a chimney breast can provide more space and modernize a room—but if done incorrectly, it can compromise the integrity of your home. That’s where gallows brackets come in.

In this article, we’ll explore everything you need to know about gallows brackets supporting a chimney: what they are, when they’re used, building regulations, advantages, limitations, and more.

What Are Gallows Brackets?

Gallows brackets are L-shaped steel supports used to provide structural support to a remaining chimney stack after the removal of a chimney breast. These brackets are usually fixed to the party wall and designed to take the load of the brickwork above.

The name "gallows" comes from the resemblance to the frame used for hanging, but in construction, these brackets are purely structural. They’re an alternative to more complex and expensive structural steel beams or full chimney stack removal.

When Are Gallows Brackets Used?

Gallows brackets are typically used when:

• A chimney breast is removed at ground or first floor level.

• The chimney stack remains above the roofline.

• The wall is a solid party wall at least 215mm thick.

• The work is being done on a shared wall, often in terraced or semi-detached houses.

They’re most suitable when the chimney stack is centrally located on the wall and the load can be evenly distributed onto the brackets.

Benefits of Using Gallows Brackets

Cost-Effective

Compared to steel beams or full removal, gallows brackets offer a cheaper alternative that still meets safety standards.

Ease of Installation

They are relatively easy and quick to install by a professional builder or structural engineer.

Minimal Disruption

Since there’s no need to access the roof or disturb the chimney stack itself, it results in less disruption to the property.

Compliance with Regulations (When Applicable)

When installed under the right conditions and with correct approvals, gallows brackets meet building control requirements.

Building Regulations and Approval

In the UK, any work involving the removal of a chimney breast or alteration to structural elements must comply with Building Regulations.

Key Requirements:

• The chimney stack must be no wider than 1.2 metres.

• The wall supporting the bracket must be solid masonry at least 215mm thick.

• Brackets must be engineer-designed and securely fixed using anchor bolts.

• Structural calculations may be needed to verify the load-bearing capacity.

• In most cases, building control notification and inspection is necessary.

Party Wall Agreement:

If you share the wall with a neighbour (common in semi-detached or terraced homes), the Party Wall Act 1996 may apply. You are legally required to serve a Party Wall Notice and obtain written consent before starting work.

Failure to comply can lead to disputes and even legal action, so consulting a party wall surveyor is recommended.

Technical Specifications

Although specifications can vary depending on your property and engineer’s advice, typical gallows bracket features include:

• Mild steel construction

• L-shaped design (typically 750mm x 750mm)

• Minimum of 2 brackets spaced appropriately

• Fixed using M12 expanding anchor bolts

• Accompanied by a steel spreader plate or back plate to distribute load

A structural engineer will assess whether gallows brackets are suitable for your home and provide drawings and calculations if required.

When Gallows Brackets Are Not Suitable

Gallows brackets are not a one-size-fits-all solution. They may be inappropriate or unsafe in the following cases:

Chimney stack too wide

If wider than 1.2m, brackets might not safely support the load.

Wall too thin or not masonry

Cavity walls or plasterboard walls won’t provide enough strength.

Chimney stack not centrally located

Off-centre stacks may apply uneven loading on the brackets.

Neighbours don’t agree

If you fail to get Party Wall consent, you may be forced to halt or reverse the work.

Stack shows signs of damage or instability

In such cases, full removal or a more robust support method might be required.

Professional Advice and Safety First

Before undertaking any structural changes involving chimney breasts:

• Hire a structural engineer to assess your specific situation.

• Consult with your local council's Building Control department.

• Obtain necessary permissions, including Party Wall Notices.

• Use qualified builders or contractors with experience in gallows bracket installation.

Gallows brackets provide a safe, affordable, and minimally disruptive method of supporting a chimney stack after removing the breast. However, their suitability depends on several technical and legal factors. Always consult with structural professionals and ensure full compliance with building regulations and the Party Wall Act.

If done correctly, using gallows brackets can improve your living space while maintaining structural safety—offering a practical solution to a common home renovation challenge.

For more information you can call Express Party Wall Surveyor at 020 3633 0823 or contact us