Cross stairs can be open stairs, which are common in old libraries.
The difference between the two is that the scissors staircase belongs to a kind of cross staircase in structural form.
According to the fire regulations, scissors stairs are strictly safe stairs.
Scissors and cross stairs are often used to evacuate dense crowds, such as gymnasiums and teaching buildings in colleges and universities.
High-rise buildings often use cross stairs as safety stairs (also known as fire stairs). When using the safety staircase, it should be designed as a smoke-proof staircase according to the requirements of the fire protection code, with sufficient window area or smoke exhaust duct.
Scissors stairs are two straight stairs side by side, in opposite directions, and the two stairs are connected by a wall between them. Cross stairs are two double-gun stairs with a rest platform, which are arranged oppositely and communicate with each other.