Curved staircase and stair tread for curved staircase

摘要

A curved staircase (1) and a stair tread (4,5,6,7) for a curved staircase (1) capable of reducing a stock space used for stock keeping, enhancing the working efficiency for shipment without requiring a selection operation in accordance with a curve direction of a curved staircase (1), and facilitating assembly at a building site is provided.;A curved staircase A (1) is formed by asymmetrical stair treads (4,5,6 and 7) such that finishing process for enabling use as a treadboard is applied to one horizontal surface of each stair tread (4,5,6,7), which can be an upper surface when arranged in a curved portion (10) bent in the right-hand direction and the same finishing process as that for the former horizontal surface is applied to the other horizontal surface of the stair tread (4,5,6,7), which can be an upper surface when the stair tread (4,5,6,7) is inverted to be arranged in the curved portion (10) bent in the left-hand direction.