Traditional design prefabricated wooden staircase - has modular step supports each made of small boards with tongue and groove joints

摘要

The wooden staircase incorporates a stringer and a rack bar on which the steps and the risers are supported. Both the stringer and the rack bar are made of units which are arranged together and each formed on small boards (1, 2, 3) movably fixed together. Each unit fixes the end of one step and one riser. A base unit forms the straight flights of stairs, and at bends, shaped boards form quarter steps. The base unit consists of three small boards (1, 2, 3) arranged along two large vertical sides by means of tongues fitting into grooves. Banisters are fixed by one flat surface onto the outer plane of the steps, and onto one flat plane of the risers. The units can be adjusted in height and length.