Concrete Cover Specifications

 

Concrete Protection for Reinforcing Bars

The following specified concrete cover, as per ACI 318, should be provided for reinforcing bars. For bundled bars, the specified cover should be equal to the equivalent diameter of the bundle but need not be greater than 2 inches; except for concrete cast against and permanently exposed to earth, the specified cover should be 3 inches.

 

Cast-in-Place Concrete (non-prestressed)

 

	Concrerte Cover (inches)
Concrete cast against and permanently exposed to earth	3
Concrete exposed to earth or weather:
#6 through #18	2
#5 and smaller	1½
Concrete not exposed to weather or in contact with ground:
Slabs, walls, joists:
#14 and #18	1½
#11 and smaller	¾
Beams, columns
Primary reinforcement, ties, stirrups, or spirals	1½
Shells, folded plate members
#6 and larger	¾
#5 and smaller	½

 

Precast Concrete (manufactured under plant control conditions)

 

	Concrerte Cover (inches)
Concrete exposed to earth or weather
Wall panels
#14 and #18	1½
#11 and smaller	¾
Other members
#14 and #18	2
#6 through #11	1½
#5 and smaller	1¼
Concete not exposed to weather or in contact wtih ground:
Slabs, walls, joists
#14 and #18	1¼
#11 and smaller	⅝
Beam, columns
Primary reinforcement	db*
Ties, stirrups, or spirals	⅜
Shells, folded plate members
#6 and larger	⅝
#5 and smaller	⅜

*But not less than ⅝ inches and need not exceed 1½ inches.