An "oak staircase" refers to a set of stairs made from or covered with oak wood. It is a term used to describe a particular type of staircase material and design. Full definition
1st floor features a custom built kitchen with a real butcher block island, custom oak staircase and extra large door openings throughout the home. (1KBB.com)
There are a further three floors above connected by a winding oak staircase. (idealhome.co.uk)
A magnificent oak staircase is a particularly striking feature. (idealhome.co.uk)