What is the maximum tolerance for the difference between the largest and smallest riser height in any flight of stairs?

The maximum tolerance for the difference between the largest and smallest riser height in any flight of stairs is typically 3/8 inch. This requirement is in place to ensure safety and accessibility in stair design. When risers vary significantly in height, it can create a dangerous situation for individuals, as it increases the chance of tripping or falling.

The standard regulation aims to provide uniformity in riser height, making it easier for users to navigate stairs confidently. By allowing a maximum of 3/8 inch difference, the code strikes a balance between practical construction tolerances and the need for safety.

The options representing smaller tolerances, such as 1/8 inch and 1/4 inch, might be too stringent for practical construction, while a tolerance of 1/2 inch could compromise safety significantly, allowing for a much wider disparity between riser heights than is deemed acceptable. Therefore, 3/8 inch is established as the standard maximum tolerance.