As a minimum 4 rebar 1 2 inch is spaced vertically at 36 inches on center continued to within 8 inches of the top of the wall placed on the tension side the inside face of the wall.
Using rebar and concrete in basement wall.
This calculator assumes that you are using 20 foot long lengths of rebar.
If your wall is over 40 feet long it will add 2x the amount of overlap required.
Rebar is recommended for concrete that measures 5 6 inches in depth.
In slabs and walls then of an inch is required.
Mortared block sometimes is reinforced with horizontal rebar laid in the joints as support against lateral pressure such as basement backfill.
Concrete block can be laid with mortar between blocks or dry stacked and sealed with a surface bonding cement.
In general rebar in residential construction needs to have 3 inches of concrete cover or separation from soil when the concrete for footings and pads is poured against soil and if poured against forms 1 inch.
If formed concrete not exposed to earth or weather.
The type of and intended use of concrete impacts the need for rebar reinforcement.
A sideways force against a basement wall puts one face of the wall in tension see figure 1 next page and concrete s tensile strength is much lower than its compressive strength.
Spacing of rebar will vary with the type of wall and construction.
Rebar must be placed at the center of or slightly above the center of the concrete slab hence why it should be a certain thickness for best results.
Designing a wall to prevent failure in bending requires a proper analysis of the soil loads and an appropriate structural design of the wall.