What horizontal load in pounds must intermediate rails or balusters withstand on an area equal to one square foot?

The correct answer reflects the standard requirement for intermediate rails or balusters in relation to horizontal loads. According to building codes, especially those concerning residential guardrails and balustrades, these vertical elements must be designed to withstand a horizontal load of 50 pounds applied over an area of one square foot.

This requirement is significant because it helps ensure safety by preventing accidental falls through gaps in the guardrails or balustrades. By ensuring that they can handle this specified load, builders and inspectors contribute to the overall integrity and safety of the structure. This standard is widely accepted within the building industry and forms a foundational aspect of construction practices concerning stairways, decks, and similar structures.