FV125 Large Ventilated Cavity Barrier

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FV125 Large Ventilated Cavity Barrier is a specially formulated fire rated rock mineral fibre section with an integral high expansion intumescent seal attached to the leading edge, suited to an open state cavity with a maximum air gap of 25 mm.

Fire Rating: 180 Minutes

Usage/purpose

FV125 is a fire rated product designed to act as an external wall cavity barrier at the required locations such as compartment floors, around windows, doors, etc. and within uninsulated cavities requiring permanent (open-state) ventilation, to reinstate fire resistance performance. In the event of a fire FV125 will expand to close the final gap between its leading edge and the internal face of the cladding. It provides effective fire resistance, for integrity and insulation for up to 180 minutes depending upon the construction of the external walls. FV125 is designed for use within a designed cavity of up to 450 mm, and once installed will close the remaining free air gap (in front of the 4 mm thick cavity barrier) of 25 mm.

Always read SDS, pre-application guidance and relevant application detail prior to application. Ensure the latest documents are downloaded prior to every project commencement.

Maximum free air gap for this cavity barrier is 25 mm, the space in front of the intumescing strip on the face of the cavity barrier to the rear of the external wall surface.
Ventilated cavity barriers should be installed in a continuous run (with the exception of abutting up to full fill vertical cavity barriers). Where this is not possible, details should be agreed with the projects principal designer and a fire engineer.
Horizontal cavity barriers should be installed adjacent and tightly abutted to any vertical cavity barriers, the vertical cavity barriers should be installed first.
An identification label is attached to the intumescing face of the cavity barrier, ensure this faces out into the open cavity. Also ensure the label is visible and legible and reads the right way up. If the identification label is not legible please contact our Technical Support, the label is important in terms of identifying the product in the future, for example
during fire risk assessments or fire safety inspections.
Cavity barrier fixing brackets, both Small (FO306 Stainless Steel Brackets) or Large Steel Brackets (FO307 Large Steel Brackets) must not penetrate through the face of the cavity barrier. Screws for direct fixing and fixings to secure brackets are not supplied by Tremco CPG Europe.
The brackets used to fix the horizontal cavity barrier must be installed with the spike inserted centrally (horizontally) to the rock mineral wool section of the cavity barrier with the bracket fixed above and not below the cavity barrier.
The use of tape is not required over the joints between the lengths of cavity barrier, and if used should not be applied over the face of intumescent material.
The cavity barrier must be installed following the installation methods described below. The cavity barrier must not be penetrated by any other mechanical or electrical services.

Safety data sheet must be read and understood before use.

  • Up to 180 minutes fire resistance tested in accordance with ASFP TGD19 Guidance.
  • Maintains a 25 mm air gap.
  • Up to 450 mm cavities tested.
  • Fixing brackets included as standard.
  • Allows ventilation of cavities, reducing the need for cavity trays or weepholes.
  • Lightweight for easy and quick installations.
  • No maintenance required after installation.
FV125 Performance Table (en-GB).pdf Performance Table
FV125 Safety Data Sheet (en-GB).pdf Safety Data Sheets
FV125 Technical Data Sheet (en-GB).pdf TDS
Nullifire Cavity Barriers Leaflet (en-GB).pdf Flyer