Definition
Cavity Barrier
A cavity barrier is a construction element installed within concealed voids — including ceiling spaces, roof voids, and wall cavities — to interrupt the paths along which fire and smoke can travel unseen and unimpeded. Cavity barriers form a critical part of a building's compartmentation strategy and must be present and undamaged, as identified during any fire risk assessment or compartmentation survey.
Terms mentioned in this definition
Related Terms
- Passive Fire ProtectionPassive Fire ProtectionPassive fire protection (PFP) comprises the structural and material elements built into a building to contain or slow the spread of fire and smoke without requiring activation — including compartmentation, fire doors, fire stopping, cavity barriers, and structural fire protection. PFP elements must comply with Approved Document B and are assessed as part of a fire risk assessment.View definition
- CompartmentationPassive Fire ProtectionCompartmentation is the division of a building into fire-resisting cells using walls, floors, ceilings, and fire doors, designed to contain a fire within its compartment of origin for a specified period — typically 30 or 60 minutes. It is a core element of passive fire protection and is required in all non-domestic premises under Approved Document B and assessed through every fire risk assessment.View definition
- Fire StoppingPassive Fire ProtectionFire stopping is the sealing of penetrations in fire-resisting walls, floors, and ceilings — such as gaps around pipes, cables, ducts, and conduits — using approved materials that restore the required fire resistance rating. Inadequate or missing fire stopping is one of the most frequently cited failures identified during fire risk assessments and compartmentation surveys.View definition
- Fire Risk AssessmentFire Risk AssessmentA fire risk assessment is a systematic examination of a premises to identify fire hazards, evaluate the risk to people, and implement or recommend appropriate fire safety measures. All non-domestic premises must have a suitable and sufficient fire risk assessment under the Regulatory Reform (Fire Safety) Order 2005, carried out by a competent person and reviewed regularly — or whenever significant changes occur.View definition
- Approved Document BFire Regulations & StandardsApproved Document B is the UK Building Regulations guidance document covering fire safety in the design and construction of new buildings and major extensions. It sets requirements for means of escape, internal fire spread, compartmentation, external fire spread, and access for the fire and rescue service, and references British Standards — including BS 5839 and BS 5266 — for specific technical requirements.View definition
Frequently Asked Questions
A cavity barrier is a construction element installed within concealed voids — including ceiling spaces, roof voids, and wall cavities — to interrupt the paths along which fire and smoke can travel unseen and unimpeded. Cavity barriers form a critical part of a building's compartmentation strategy and must be present and undamaged, as identified during any fire risk assessment or compartmentation survey.
Requirements for cavity barrier in the UK depend on the type of premises and applicable legislation, including the Regulatory Reform (Fire Safety) Order 2005 and relevant British Standards. The responsible person for a premises must ensure adequate fire safety provisions are in place. The British Fire Consortium can provide guidance — contact our team or search our member directory to find a qualified specialist.
Cavity Barrier and Passive Fire Protection are related fire safety concepts but serve different purposes. See our individual glossary entries for detailed definitions. For expert guidance on which applies to your premises, consult a BFC member company.
The British Fire Consortium offers EAL Level 3 accredited training covering fire safety systems including topics related to cavity barrier. Our courses are the only nationally recognised Level 3 qualifications across all fire disciplines. View our training courses or use the member directory to find a qualified trainer near you.