No cover has been specified for concrete basement walls containing Number 5 bars. We are concerned about the danger of corrosion if the steel is too close to the surface. How much cover is needed?
ACI 318 requires 3-inch cover on the side of any wall cast directly against the earth. If the concrete is to be cast against forms and later exposed to the earth or the weather, 1 1/2-inch cover is needed at the exterior surface. On the inside surface of the wall at least 3/4-inch cover is needed. Cover requirements for footings, walls, columns, beams, slabs and joints are given in the ACI 318-71 Building Code, Section 7.14. In some instances the cover depends on the bar size.