When are main stairways typically built or installed in the construction sequence?

Main stairways are typically installed after the flooring is laid to ensure structural integrity and protect the stairs from damage during the construction process. If stairs were installed beforehand, they could be subjected to heavy foot traffic, tool use, and the potential for accidental damage from other construction activities. Installing them after the flooring ensures that the stairway is correctly aligned with the finished floor surface, guaranteeing a seamless transition and proper fit for both safety and aesthetics. Additionally, this sequence allows for any adjustments to be made more easily concerning the finished floor height.

The other choices present stages that are less conducive to stair installation due to logistics and potential for damage. For instance, installing stairs before wall installation could complicate access and create challenges with alignment. Installing them prior to foundation work is not possible since the foundation is the base that supports the entire structure, and flooring installation comes after the main structural elements, including the stairs, in the sequence. Lastly, placing stairs after windows would also run the risk of damage during window installation and might complicate the overall workflow of the construction site.