Horizontal cavity barriers are also referred to as open state barriers. The use of horizontal cavity barriers ensures that the system will drain any moisture within the façade construction, whilst maintaining airflow and in the event of fire, provide an effective hot smoke and fire seal. Open State Cavity Barriers are made from polythene sleeved stone wool and intumescent material.
These have been developed to meet the requirements for cavity barriers used in drained and ventilated façades.
In the event of exposure to fire, the intumescent rapidly expands and fully seals the purposely designed ventilation gap, formed at the time of installation, between barrier and the rear of the cladding.
Open State Cavity Barriers offer an effective fire barrier for open state voids up to 425mm in width for up to 120 minutes.