Which of the following is NOT a basic type of steel stair?

• A. Spiral
• B. Straight
• C. Curved
• D. Ramp

Answer: (D)

Understanding stair classifications in steel construction helps distinguish how each shape carries loads and fits in a building’s layout. The basic steel stair configurations you’ll encounter are straight stairs, curved (radius) stairs, and spiral stairs. A straight stair runs in one unbroken line from bottom to top, which makes it simple to frame and install. Curved stairs use a curved stringer and landings to change direction smoothly, requiring more complex fabrication and precise geometry. Spiral stairs wrap around a central column, saving floor space and creating a distinct structural pattern.

A ramp, on the other hand, is a sloped surface designed for wheeled or easy-access rather than a stair run. It’s treated as a separate accessibility element with its own slope requirements and framing considerations, not a basic stair type. So ramp is not categorized as a basic type of steel stair.