What action is needed where fire resisting ducts pass through oversized openings in fire resisting elements of construction?
ANSWER. Any oversized gap shall be reduced in size such that the additional fire penetration seal around the duct can function as fire tested within a maximum residual opening. Responsibility for the satisfactory performance of each element of building construction (e.g. walls, floors, cavity barriers, etc.) lies with the installer of each particular element. The ‘change over’ of responsibility occurs at the interface between the fire resisting ductwork and the elements. It is imperative that the interface detail does not compromise the fire performance of either the element of building construction or the fire rated duct. The building designer, mechanical services designer and the installer all have a responsibility to pay ‘due care’ to this detail.
