What is the maximum height of risers allowed for spiral stairs as per RA 9514?

The maximum height of risers allowed for spiral stairs as specified in RA 9514, which is the Fire Code of the Philippines, is 180 mm. This provision is in place to ensure the safety and accessibility of spiral staircases. The measurement is set at this height to create a reasonable balance between comfort and safety for users. Taller risers can make the stairs more difficult to navigate, increasing the risk of accidents, particularly in emergency situations where quick egress is necessary.

Spiral staircases often serve as secondary means of egress, and their design must adhere to specific building codes to facilitate safe and quick evacuation during emergencies. The stipulation of a maximum riser height helps ensure that these staircases can be used effectively while reducing the likelihood of missteps or falls. This requirement reflects considerations of human factors in design, ensuring that all individuals can safely ascend or descend these stairs without undue strain or difficulty.