The different types of stairs include box, cap, double cap, winder and open. There are also bullnose stairs that work as part of a staircase. Different types of stairs are identified by their tread, riser and nosing.
Box stairs have a rectangular shape that is closed in on both sides. There are no posts placed through these types of stairs. Cap stairs, also know as wrap stairs, are rectangular in shape. The stairs are closed on one side and opened on the other. There are typically two posts that go through the stairs on the open edge to secure the railing of the staircase.
Double-cap stairs are similar to regular cap stairs, although this type is open on both sides. There are typically two posts placed on both sides of each stair to secure the railing. Winder stairs, also known as pie stairs, are used to create a turn in a staircase. These stairs are wide on one side and narrow on the other to create a triangular shape. They are sometimes used to create a full curving staircase.
Open stairs, also known as backless stairs or Hollywood stairs, are free of risers. This allows the back of each stair to be open to the floor below. Bullnose stairs are the stairs that are located at the bottom of a staircase. They have a rounded edge that extends outward past the edge of the other stairs.