Rebar take-off in EstiMatrix: bar sizes, unit weights and lapping allowance

Reinforcement is usually the largest single cost in an RCC building, and it is measured in kilograms — not cubic metres. EstiMatrix detects reinforcement items automatically and gives them their own take-off sheet.

When the rebar layout appears

Any item whose unit is kg or MT and whose description mentions reinforcement, deformed bar, M.S. rod, re-bar or a steel grade (500W, Grade 60, 72.5 …) opens in the rebar layout — whether it came from the PWD SoR, a custom item or your library. You can force it with Sheet layout → Rebar.

The columns

Next to the diameter, the sheet shows the unit weight applied — for example 0.270 kg/ft for 12 mm — so a checker can verify the multiplier.

Worked example

12 mm bars measured in feet: Nos = 2, Length = 3 ft, Members = 5.

• Total length = 2 × 3 × 5 = 30 rft
• Weight = 30 × 0.270 = 8.10 kg

Unit weights used

EstiMatrix uses the standard table values (d²/162.2 kg/m, rounded as printed):

Why d²/162? See rebar weight calculation explained.

Lapping and wastage

Bars are sold in 12 m (39.37 ft) lengths, so long runs need laps, and cutting leaves offcuts. Set Lapping / wastage % on the item — quick buttons for 0, 5, 7.5 and 10 % — and it is added to the take-off weight. The total row states the allowance used.

For detailed lap lengths, hooks and bend deductions bar by bar, use the bar bending schedule instead and set the item's quantity source to BBS.

Rebar summary by diameter

Below the sheet, the rebar summary lists kg and MT per diameter for this item and for all rebar take-offs in the project — exactly what procurement needs to order steel. The Material requisition combines it with the bar bending schedule.

Kilograms or metric tons

If the BOQ item unit is MT, the take-off weight is divided by 1,000 automatically; the summary always shows both.