The number of steps of each staircase in primary and secondary schools should not be less than 3 steps and not more than 18, and should meet the following requirements:

(1) The width of stair steps in all kinds of primary schools shall not be less than 0.26m and the height shall not be greater than 0.15m. ..

(2) The gradient of stairs shall not be greater than 30.

2. The clear width of stairwell between two stairs should not be greater than 0. 1 1m. When it is greater than 0.11m, effective safety protection measures should be taken. The horizontal clear distance between two step handrails should be 0.10m ~ 0.20m ~ 0.20m. ..