Material is usually 40-50% of project cost — which means even a small wastage gap above benchmark is often the single largest line item a contractor never explicitly measures.
Ask a contractor how much cement or steel their last project wasted, and most will give a shrug and a rough guess. That guess is usually wrong — not because anyone is being careless, but because wastage is almost never measured against a benchmark in real time. It is inferred, after the fact, from the gap between what was bought and what the BOQ said should have been enough.
For cement: bag handling loss, imprecise mixer batching, over-thick plaster and PCC "for safety," and curing water washing away surface cement. For steel: cutting-length rounding, excess lap lengths beyond IS 456 minimums, and offcuts too short to reuse. None of these are dramatic on their own — a bag torn here, a slightly-thick plaster coat there — but they recur daily, on every element, for the life of the project.
Material is purchased in bulk against a rough monthly estimate and consumed against a running total — not reconciled bag-by-bag or bar-mark-by-bar-mark against work actually executed. The only point where the gap becomes visible is final reconciliation, by which point the extra cost has already been paid and is usually attributed to "material price inflation" rather than the real cause.
On a project using ₹80 lakh of cement and steel combined, the difference between disciplined wastage (3%) and typical unmeasured wastage (6-7%) is roughly ₹2.4-3.2 lakh — money that never appears as a single expense, just as a slightly-worse-than-planned material budget month after month.
The highest-leverage change is not buying better material or hiring stricter supervisors — it is reconciling material issued against BOQ-planned quantity for work actually completed, on a daily or weekly cadence rather than at project close. Once that habit exists, wastage outliers get caught in week two, not month six.
Contractors who keep wastage close to benchmark share one habit: they reconcile material issued against BOQ-planned quantity for work actually completed on a weekly cadence, not at project close. This turns a 3-point wastage gap into something caught and investigated in week two, when the cause (a specific pour, a specific vendor batch, a specific crew) is still identifiable — instead of a lump-sum surprise at handover with no way to trace back what happened.