Stairs come in different shapes, sizes, and configurations. Here are the different types of stairs typically found in a home:
Box Stair
- A box stair is straight, has no railing posts, and is closed in on all sides.
- It is typically approximately 3′ wide.
- The usual allowance for the tread (the flat part you step on) is 10″, and 8″ for the riser (the back of the stair). Therefore, for every box stair, you require 3′ (or the width of your stair) x 18″ of carpet.
Cap Stair
- A stair that has one open side with railing posts on it is known as a cap stair.
- It has the same measurements for the tread and riser as a box stair (combined 18″).
- You will need approximately 4′ of carpet to cover the width, to allow the carpet to flow through the posts and wrap around the outside of the stair.
- If your stair is open with a railing on both sides of it (a double cap) you will need approximately 5′ of carpet to cover the width.
Pie Stair/Winder
- A curved stair is called a pie stair or winder.
- The general guideline is that you will require 4′ (or the width of the stair) x 30″ of carpet for every pie stair — this allows for some maneuvering of the carpet by the installer to find the best fit.
Open Stair
- An open stair (sometimes called a Hollywood stair) is a stair with no backing.
- Measure your stair to determine the width.
- You will need approximately 20″ of carpet to wrap completely around the stair.
Bullnose
- A bullnose stair is often found at the bottom of a staircase.
- It is wider than the rest of the stairs, and is rounded on one or both sides.
- The tread and riser combined have the same measurements as a box stair (18″).