Covering up the Fire cavity Barrier face with foil Tape
The cavity barrier face has been covered with foil tape, apparently masking an inadequate fit rather than correcting it. Foil tape cannot replace the required physical contact and compression between a closed-state cavity barrier and the rear of the façade panel, nor can it bridge gaps as part of an untested detail. The torn and loosely applied tape also conceals the barrier condition and prevents proper inspection. The tape should be removed and the barrier refitted or replaced in accordance with the tested system and manufacturer’s installation requirements.
- NCQLE reference
- NCQLE-2026-00004
- Quality topic
- Installation quality
- Lesson type
- Failure
- Evidence rating
- Documented
- Published
- 31 July 2026
- Last reviewed
- 31 July 2026
Evidence basis: Supported by reviewed project documentation. This learning is provided for professional consideration and does not replace project-specific competent advice, statutory duties or contractual requirements.
Context
During inspection of the external-wall cavity, a mineral-wool fire cavity barrier was found with its exposed face extensively covered by foil tape. The tape appeared to have been used to conceal or bridge damaged and poorly fitted areas rather than as a permitted joint treatment. The installation did not demonstrate the required continuous contact and compression between the closed-state cavity barrier and the rear of the façade panel, raising concerns about whether the installed detail could achieve its intended fire and smoke performance.
The transferable lesson
Foil tape must never be used to conceal poor workmanship, bridge gaps or compensate for an incorrectly sized or positioned cavity barrier. The barrier’s fire performance depends on installation in accordance with its tested system, including the correct dimensions, compression, support, joints and contact with the rear of the façade panel where a closed-state barrier is specified. Tape should only be used where expressly permitted by the manufacturer. All cavity barriers must be inspected and photographed before concealment.
Recommended action
Remove the foil tape and expose the complete cavity barrier for inspection against the approved design and manufacturer’s tested installation detail. Replace any damaged, undersized or poorly fitted barrier rather than attempting further patch repairs. Confirm the correct compression, continuous contact with the rear of the façade panel, support fixings, joints and interfaces. Inspect comparable locations for the same defect and record the corrected installation photographically before the façade is closed. Any non-standard detail should receive written approval from the system manufacturer and competent fire/façade specialist.
Limitations and application
The finding is based on the accessible area shown and does not establish the condition of the full cavity barrier or adjacent installations. The approved design must confirm whether a closed-state or open-state barrier is required, as their installation principles differ. Foil tape may be permitted for specific joints or facing repairs only where included within the manufacturer’s tested system. Intrusive inspection and review of the product certification, approved details and installation instructions are required before determining the extent of remedial work.