Fire Cavity Barrier hanger failure after 8 years
The cavity-barrier support hanger has suffered severe premature corrosion after approximately eight years, with extensive rusting, delamination and apparent loss of metal section around the fixing and along the support. Its ability to securely retain the cavity barrier can no longer be relied upon, creating a risk of movement, gaps and reduced fire performance. Comparable locations should be inspected and defective hangers replaced with compatible, suitably corrosion-resistant components forming part of the approved cavity-barrier system.
- NCQLE reference
- NCQLE-2026-00003
- Quality topic
- Product compliance
- Lesson type
- Failure
- Evidence rating
- Multi Project
- Published
- 31 July 2026
- Last reviewed
- 31 July 2026
Evidence basis: Supported by evidence from multiple projects. This learning is provided for professional consideration and does not replace project-specific competent advice, statutory duties or contractual requirements.
Context
During an inspection of the external-wall cavity approximately eight years after completion, a concealed metal hanger supporting the fire cavity barrier was exposed. The hanger showed severe corrosion and apparent loss of section, despite being required to retain the barrier securely throughout the building’s service life. The finding raised concerns about the original material specification, corrosion protection, moisture exposure and the condition of similar supports elsewhere on the building.
The transferable lesson
The long-term performance of a cavity barrier depends on the durability of its supports as well as the barrier itself. Hangers and fixings must form part of the approved system and be specified for the anticipated cavity environment, moisture exposure and required service life. Material grade, protective coating and compatibility with adjacent metals must be verified before installation. Supports should be inspected and photographed before concealment, with full product traceability retained. A failure at one location should trigger a risk-based survey of comparable installations.
Recommended action
Arrange an intrusive, risk-based survey of the affected cavity barrier and comparable locations to establish the extent of corrosion. The cavity barrier manufacturer and competent fire/façade specialist should confirm the approved replacement detail. Severely corroded hangers must be replaced, not simply cleaned or coated, with compatible, corrosion-resistant supports forming part of the approved system. Investigate and correct any moisture-ingress source, inspect the cavity barriers for movement or gaps, and photograph and record all remedial work before the façade is closed.