Fire Stops In Cavity Walls

What are cavity barriers and fire stops.

Fire stops in cavity walls.

A cavity in the external wall can act as a chimney allowing flames hot gases and smoke to travel from one compartment of a building to another. Varley insulation cavity fire barrier has been developed to give 4 hour fire integrity and restrict the spread of smoke and flames within external masonry and timber framed walls. It can also be used for the control of sound flanking at wall junctions. The ultimate question being when do cavity closers need to have fire resistance.

Stopping the spread of fire in cavity walls. An issue that has been causing much confusion among developers at the moment is the requirement for the prevention of fire spreading within cavity walls. It s important to add solid wood blocking as well if floor joists intersect a wall so that the fire can t go up a wall and then sideways in between floor or ceiling joists. Barriers used to close concealed spaces and prevent penetration of smoke or flame to restrict the movement of fire within a building.

The bottom block stops the fire from getting into the wall cavity to begin with. One of the main challenges in these circumstances is ensuring that the breathability of the building is balanced with the ability to prevent the passage of smoke and fire through the channels. Wherever there is a concealed cavity within a building whether that is a floor wall ceiling or external façade there is a risk of fire spreading. Cavity fire barrier are strips of low resin non combustible rock fibre mineral wool sleeved in 50 micron polythene for onsite protection.

Cavity walls and ceiling voids would be considered concealed spaces and would generally be fitted with cavity barriers during construction.