Stairs are typically a maximum of 36 inches wide. Wider stairs need a reinforcement of a third stringer. Closed is where there is a back to the step. When you walk up the stairs, you cannot see through the step to the other side. Open is far less attractive and can cause a problem for a young child, if they should happen to fall on the stairs, their leg can go through and become caught or scratched.
Closed treads are the most common and favorite way to design steps in homes today.
To build your stairs, you'll need to figure out a few things, including the number of treads, the rise between treads, and the total run of the steps-the horizontal distance between the top and bottom of the stairs. With closed stringers, treads are supported by cleats fastened to the inside face of the stringers. The stairs should be a maximum of 36 inches wide. To be comfortable, the rise between steps should be about 7 inches. With gauges, mark the step's rise measurement on the short arm of a framing square and the run on the long arm.