What is the term used to describe the maximum spacing allowed between various sizes of joists or rafters?

The term that describes the maximum spacing allowed between various sizes of joists or rafters is known as "on center spacing." This specification is crucial in construction and building design, as it dictates how far apart the centers of two adjacent joists or rafters can be from each other.

Understanding this term helps builders ensure structural integrity and compliance with building codes. On center spacing is important for distributing loads evenly and providing sufficient support for the flooring or roofing materials that will be applied. Different sizes and types of joists and rafters may have different requirements, so knowing the proper on center spacing is essential for proper framing.

Other terms mentioned, such as "center spacing," are often used interchangeably, but “on center spacing” is the more technically accurate and widely accepted terminology in the industry. Similarly, "joist span" refers to the distance between the supports of a joist rather than the spacing between joists, while "rafter spacing" specifically pertains to the distance between rafters and does not encompass all types of structural supports. Therefore, "on center spacing" is the most precise term to describe the context of the question.