Cold State Height refers to the maximum height a partition can achieve under normal conditions, based on its mechanical capabilities and deflection limits (e.g., L/240 under a 200Pa load or BS 5234-2 duty limits). 

Fire State Height is the maximum height a partition can maintain during fire conditions while ensuring structural integrity and compliance with fire safety standards.

The Fire State Height is typically lower than the Cold State Height due to:

• The effects of fire on material performance when exposed to high-temperature
• The limitations of fire test height in fire test laboratories, where furnace height is restricted (e.g., maximum 3.0 meters)

It is essential to understand that the maximum height of a system under a normal (cold) state may not be applicable during a fire. In cases where the project specification does not require fire resistance for the partition system, height selection can be based on the partition’s mechanical capabilities and deflection limits. However, if fire resistance is required for the partition system, the Fire State Height should be the default reference. 

When reviewing the Siniat systems in the Drywall Manual make sure the cold state and fire state heights are read correctly:

they are either displayed in separate columns thus:

or in one column with different colour text: