Could I have some thoughts on the provision of roof void cavity barriers in residential care premises, as I am getting conflicting interpretations and 'actions' from different sources.
Under ADB and Scottish technical annexes it is based upon maximum distance between barriers eg 20m/10m.
And under HTM 05-02 firecode "With the exception of the ceiling void above operating departments, 30-minute fire-resisting barriers should be provided to subdivide concealed roof or ceiling voids. These should be positioned to coincide with subcompartment walls and walls to fire hazard rooms".
Generally, the ceiling on the top floor of a residential care home ( not many are above 3 floors), is 30 minutes fire resistance ( in new ones anyway ), so do we accept that the containment and spread in the roof void is to be contained to that void in the roof and controlled to 20 meters horizontal travel, or where a sub compartment is to be evacuated first on the floor below do we look at the interpretation that if the barrier does not follow the sub compartment line below it could spread across two sub compartments below and possibly affect the means of escape below for PHE.
The hazard room situation should be served by the 30min. ceiling ? Should it ?
I suppose a question could be in 'progressive horizontal evacuation' buildings do we follow the lines of the floor below, and is the principle of ADB meant to be for single stage evacuation strategies ?
The problem with Fire Safety Engineering is everyone is convinced they are right !
