bgadaspen
Registered User
Hello,
We are working to better understand the requirements for fire-rated assemblies in a small employee housing building. This group-R3, type VB, NFPA 13D sprinklered building is a single story, slab on grade with pre-engineered gable truss roofs.
We have two conditions where fire paritions are required: at corridors, and where sleeping units abut each other.
Our understanding would be that where these 1 hour fire paritions are required, 708.4 would require that they are continuous to, in our case, a 1 hour rated membrane at the bottom of the truss ceiling.
Where we are hung up is on whether or not all other walls supporting the trusses would then need to be fire rated. Our logic is a follows:
-708.4 requires "The underside of a floor/ceiling or roof/ceiling assembly having a fire-resistance rating that is not less than the fire-resistance rating of the fire partition."
-711.2.3 (supporting construction for horizontal assemblies) requires "The supporting construction shall be protected to afford the required fire-resistance rating of the horizontal assembly supported."
Does the requirement for one wall that must be a fire partition effectively create the requirement that all walls and ceilings on the fire partition separated spaces need be fire rated? Are we missing something here? It seems that the intent is to stop fire from moving from one side of the partition to the other. Why would it matter if the wall on the other side of the room from the partition is fire rated or not? The fire wouldn't make it to that wall due to the fire parition and rated ceiling.
Thank you all.
We are working to better understand the requirements for fire-rated assemblies in a small employee housing building. This group-R3, type VB, NFPA 13D sprinklered building is a single story, slab on grade with pre-engineered gable truss roofs.
We have two conditions where fire paritions are required: at corridors, and where sleeping units abut each other.
Our understanding would be that where these 1 hour fire paritions are required, 708.4 would require that they are continuous to, in our case, a 1 hour rated membrane at the bottom of the truss ceiling.
Where we are hung up is on whether or not all other walls supporting the trusses would then need to be fire rated. Our logic is a follows:
-708.4 requires "The underside of a floor/ceiling or roof/ceiling assembly having a fire-resistance rating that is not less than the fire-resistance rating of the fire partition."
-711.2.3 (supporting construction for horizontal assemblies) requires "The supporting construction shall be protected to afford the required fire-resistance rating of the horizontal assembly supported."
Does the requirement for one wall that must be a fire partition effectively create the requirement that all walls and ceilings on the fire partition separated spaces need be fire rated? Are we missing something here? It seems that the intent is to stop fire from moving from one side of the partition to the other. Why would it matter if the wall on the other side of the room from the partition is fire rated or not? The fire wouldn't make it to that wall due to the fire parition and rated ceiling.
Thank you all.