Apparent ready mixed concrete shortages are caused by:

• Miscalculation of form volume or slab thickness when actual dimensions exceed the assumed dimensions by even a fraction.
• Deflection or distortion of the formwork.
• Irregular subgrade & its settlement.
• Smaller quantities wasted or used in incidental works for large pours.

To ensure sufficient supply of ready mixed concrete:

• Measure formwork accurately & order sufficient quantity to finish the job.
• For large pours, include an allowance of about 2% over planned dimensions to account for wastage & potential increased thicknesses.
• Towards the end of large pours, carefully measure the remaining volume & confirm the closing quantity to the RMC supplier.