Specified Footing & Formwork Quantity Takeoff

Preparation checklist

Start with the drawing revision, detail callouts, and the supplier's current ordering terms. A quantity takeoff is strongest when it preserves what the documents say instead of converting a vague sketch into an invented footing or form design.

• Mark each specified strip, rectangular pad, and cylindrical pad as a separate concrete section.
• Mark a junction overlap only if two entries describe the same physical volume. Record its dimensions or supplied volume and subtract it once.
• Trace only the edges explicitly selected to be formed. Mark supported, excavated, adjacent, or otherwise unformed edges as excluded rather than assuming they need boards.
• Obtain the actual stock-board length, board-course count, any confirmed supplier increment, and any project-approved allowance. These are inputs, not defaults supplied by this guide.
• Keep concrete delivery, boards, stakes, fasteners, reinforcement, excavation and labour as separately scoped lines.

What to measure and how to record it

For a rectangular strip or pad, record length × width × depth in one unit system. Its volume is L × W × D. For a cylindrical pad, record diameter and depth: volume is π × diameter² ÷ 4 × depth. Add only sections that are different physical concrete; then subtract a known shared-junction volume once. The Concrete Footing Quantity Calculator keeps those section, overlap, allowance, supplier-increment, and optional-price stages separate.

For formwork, record each selected edge as its own run: formed length, formed height, number of board courses, and stock-board length. Contact area is formed length × height. Board pieces per course are ceil(run length ÷ stock length), then multiplied by courses. The Concrete Formwork Calculator rounds each entered run independently by default, so a remainder from one edge is not silently used on another.

For broader concrete-shape and supplier-yield context, see the live Concrete Shapes and Screed Bag Yields guide. It covers different quantities; it does not replace this selected-edge formwork takeoff.

Worked footing quantity (C11, illustrative)

This synthetic example uses one specified strip and four separate rectangular pads. It deliberately makes no recommendation about whether these dimensions are suitable.

1. Strip: 10 m × 0.4 m × 0.2 m = 0.800 m³.
2. Four pads: 4 × (0.6 m × 0.6 m × 0.25 m) = 4 × 0.090 m³ = 0.360 m³.
3. Net concrete: 0.800 m³ + 0.360 m³ − 0.000 m³ entered overlap = 1.160 m³.
4. Order quantity with no allowance: 1.160 m³ × (1 + 0%) = 1.160 m³.
5. Illustrative supplier increment: ceil(1.160 m³ ÷ 0.25 m³) = 5 increments, so 1.250 m³ purchased. The 0.25 m³ increment is an example input, not a supplier recommendation.

Notice the three useful records: 1.160 m³ net geometry, 1.160 m³ allowance-adjusted order basis, and 1.250 m³ purchased after the hypothetical increment. Do not price a rounded supplier quantity as if it were the installed geometry.

Worked formwork quantity (C13, illustrative)

For a 5 m × 4 m rectangle, assume all four edges are explicitly selected as formed, each is 0.2 m high, one board course is used, and stock boards are 3 m long. These are fixture values, not formwork instructions.

1. Formed length: 5 m + 4 m + 5 m + 4 m = 18 m.
2. Contact area: (5 m × 0.2 m) + (4 m × 0.2 m) + (5 m × 0.2 m) + (4 m × 0.2 m) = 3.6 m².
3. Boards on each run: ceil(5 m ÷ 3 m) = 2; ceil(4 m ÷ 3 m) = 2. With one course, the four runs need 2 + 2 + 2 + 2 = 8 boards.
4. Purchased board length: 8 boards × 3 m = 24 m of stock length.

Contact area describes the selected face area; it is not a board count. Board count follows the stated stock length and independent-run rounding. Stakes should be a separately supplied manual count or a project-selected spacing/end convention, never inferred from this illustrative layout.

Changed-input comparison

Change only one input at a time to see which quantity moves. In the footing example, applying a 10% order allowance changes the ordered quantity to 1.160 m³ × 1.10 = 1.276 m³; the net geometry remains 1.160 m³. With the same illustrative 0.25 m³ supplier increment, ceil(1.276 ÷ 0.25) = 6 increments, or 1.500 m³ purchased.

In the formwork example, instead mark one 5 m edge unformed. The selected formed length becomes 18 m − 5 m = 13 m; contact area becomes 3.6 m² − (5 m × 0.2 m) = 2.6 m²; and the independently rounded board count becomes 6 boards. That is a scope change, not a reason to assume the excluded edge needs no support or preparation.

Common ordering mistakes

• Double-counting junctions: subtract a volume only when the entries actually overlap; do not subtract a guessed crossing volume.
• Hiding allowance in geometry: retain net volume, allowance-adjusted order quantity, and supplier-rounded purchase quantity as separate labelled values.
• Using perimeter for every edge: a selected-edge formwork takeoff can be less than the geometric perimeter when an edge is unformed.
• Turning contact area into stock count: contact area helps describe formed face area; stock boards must still be cut and rounded from each run.
• Pooling offcuts without a stated policy: do not reduce independently rounded board counts because an offcut might be reusable.
• Choosing construction details from an estimator: sizes, mix, board system, stakes, reinforcement, and safety controls come from the responsible project documents and supplier/system information.

Practical purchase or estimate checklist

• Attach the drawing revision and identify each measured section/run by location.
• List net concrete, entered overlap, allowance, supplier increment, and supplier-rounded purchase quantity with units.
• List selected formed edges, each run's height, board courses, stock length, independently rounded board count, and contact area.
• State the source of every allowance, product property, stock length, stake count, price, delivery minimum, and tax; label unknown prices as unpriced rather than zero.
• Ask the supplier to confirm mix/product, availability, increment, delivery conditions, returns, and lead time; ask the responsible project team to confirm all structural and formwork scope.