Unless otherwise specified, the standard guideline for spacing contraction joints is to space them in feet at what ratio to the slab depth in inches?

The standard guideline for spacing contraction joints in concrete slabs is based on the depth of the slab. Specifically, contraction joints typically are spaced at a ratio of 2.5 times the slab depth in inches. This means that for every inch of slab depth, the contraction joints should ideally be spaced 2.5 feet apart.

This guideline helps control cracking due to shrinkage as the concrete cures and dries. By following this ratio, you can ensure that the joints are adequately placed to manage the stresses that occur in the concrete.

Understanding this spacing is crucial in construction and concrete work to ensure structural integrity and longevity of the pavement or slab being poured.