Stair stringer for staircase, has multilayer structure, particularly three-layer structure, where layers are equipped with receiving mediums for receiving of fastening elements

摘要

The stair stringer (3) has a multilayer structure, particularly three-layer structure. The layers are equipped with receiving mediums for receiving of fastening elements. The receiving medium of one layer is covered by another layer of the stair stringer. Two or more layers comprise different outline shapes or outline sizes. An independent claim is also included for a staircase.