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How to Calculate Rebar for a Slab
Formula
Rebar (reinforcing bar) strengthens concrete by resisting tensile forces. Grid spacing of 12 inches on center is standard for residential slabs.
Number 4 rebar (1/2-inch diameter) weighs 0.668 lbs per foot and is the most common size for residential foundations and slabs.
Common use cases:
- Concrete slab reinforcement
- Foundation rebar grid
- Retaining wall reinforcement
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