Calculate reinforcement steel quantities for concrete slabs and footings. Enter slab dimensions, mesh type, and spacing to get weight, number of bars, and cost.
Calculate slab areas for formwork, mesh, and damp-proof membrane
A193 (6mm wires at 200mm) is used for light-duty slabs like patios. A252 (8mm wires at 200mm) is standard for driveways and house floors. A393 (10mm wires at 200mm) is used for heavy-duty industrial slabs. The number refers to the cross-sectional area in mm²/m.
Mesh sheets must overlap by at least 300mm (one wire spacing) at all joints. This overlap is included in the waste allowance — order 5-10% extra to account for laps and cuts.
Strip footings rarely need reinforcement on stable ground. When required (clay, made ground), use A193 or A252 mesh placed on 50mm concrete spacers below the pour. For pad footings, reinforcement is almost always required.
Minimum 50mm cover for footings in non-aggressive soil. 75mm for aggressive ground conditions. Use spacer blocks to maintain cover during the pour — inadequate cover leads to corrosion and concrete failure.
A = slab_length × slab_width
sheets = ceil(A × (1 + waste%) / sheet_area)
weight = A × kg_per_m² (mesh type dependent)
cost = sheets × price_per_sheet
Reinforcement design is structural engineering. For load-bearing slabs, footings, retaining walls, or any building-regulation-controlled concrete work, consult a structural engineer. Incorrect reinforcement can lead to structural failure. Always follow engineer specifications and building control approval.
Use A252 mesh (8mm wires at 200mm spacing) for driveways and house floor slabs. For patios and shed bases, A193 is sufficient. For heavy-duty industrial slabs, use A393.
Area = 20 m². Standard mesh sheet is 4.8m × 2.4m = 11.52 m². With 5% waste: 21 m² needed. Sheets = ceil(21 / 11.52) = 2 sheets. Weight at 2.47 kg/m² (A252): 20 × 2.47 = 49.4 kg.
A252 mesh sheets (4.8m × 2.4m) cost approximately £30-45 per sheet in the UK. A193 is about £20-30. A393 is about £50-70. Prices vary with steel market fluctuations.
Most strip footings on stable ground don't need reinforcement. On clay, near trees, or for pad footings, building control may require mesh. A structural engineer can advise.