Fire resistance of wall elements is provided in Eurocode 6 and many manufacturers provide convenient tables for their products. The required solution will depend upon whether the wall is loadbearing or non-loadbearing. Masonry walls (non-loadbearing and loadbearing) with no finishes often have 2 hours or more fire resistance with only 100mm thickness. Fire rarely governs the design of masonry walls, but detailing of junctions and ensuring good workmanship is important.
Cavity barriers and fire stops are required for all forms of construction to limit spread of fire within and between structures.
Cavity Barrier: purpose is to close a concealed space against penetration of smoke or flame, or to restrict movement of smoke or flame within such a space.
Fire Stopping: purpose is to ensure the integrity of a fire compartment - the fire stopping has at least the same fire resistance as the compartment (it is not a cavity barrier)
Approved Document B Fire Safety stipulates where cavity barriers are required and provides the parameters for designing locations for fire compartmentation. Typical locations of cavity barriers and fire stops are shown on diagram below. Pre- calculated Thermal bridging details provided by the industry include the fire cavity barriers when needed at junctions.