How do we define a "fire rated wall" in a normal office building. Is it a practice that a fire damper is fixed on every wall that the duct is passing thru???
There are different fire rating requirements for different walls. Typical tenant partitions in offices are one-hour rated and fire dampers are not required in ducts crossing one-hour walls in sprinklered buildings. The two hour walls are typically stairwells, shafts, floor boundaries and some utility spaces. Dampers are required at these partitions.