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What spacing is typical for members in a concrete joist system?

  1. 12"-16"

  2. 24"-36"

  3. 36"-48"

  4. 48"-60"

The correct answer is: 24"-36"

In a concrete joist system, the typical spacing for members is generally between 24 to 36 inches. This spacing allows for adequate load distribution while providing structural integrity and support for the spanning components of the system. The choice of this spacing reflects considerations of both structural performance and cost efficiency, enabling the joist system to efficiently carry the loads imposed on it. Spacing that is too narrow may increase material costs and excessive labor, while spacing that is too wide can lead to insufficient support, resulting in potential structural issues. The selected range of 24 to 36 inches strikes a balance that meets engineering requirements, facilitates construction, and adheres to building codes, which is why this option is the correct answer.