Reinforcement Cover in Precast Members

Less concrete cover is required for reinforcement in precast-concrete members manufactured under plant control conditions than in cast-in-place members because the control for proportioning, placing, and curing is better. Minimum concrete cover for reinforcement required by ACI 318-99 is listed in Table 9.26.
For all sizes of reinforcement in precast-concrete wall panels, minimum cover of 3⁄4 in is acceptable at nontreated surfaces exposed to weather and 3⁄8 in at interior surfaces.