PreConstruct AIA footing schedule is a table on the structural drawings — usually on the foundation plan sheet or the general notes sheet — that lists every footing type once. The foundation plan tags each footing with a mark, and the schedule says what that mark means. Reading it correctly is most of a foundation takeoff.
The columns
Most schedules carry the same three things, whatever the headings are called:
- Mark — F1, P2, WF1, SF-3. Sometimes a bare number in an unlabelled first column.
- Size — one column (“1200 × 1200 × 300”) or separate width, length and depth or thickness columns.
- Reinforcing — sometimes split into bottom and top, or longitudinal and transverse.
A metric schedule might read:
| Mark | Size (mm) | Reinforcing |
|---|---|---|
| F1 | 1200 × 1200 × 300 | 15M @ 300 E.W. bottom |
| F2 | 1800 × 1800 × 400 | (6) 20M E.W. bottom |
| WF1 | 600 × 250 | (3) 15M continuous |
And an imperial one:
| Mark | Size | Reinforcing |
|---|---|---|
| 1 | 1'-6" wide × 12" deep × cont. | (2) #5 cont. longitudinal, #4 transverse @ 16" o.c. |
| 4 | 4'-0" × 4'-0" × 18" | (4) #6 each way, bottom |
Strip footings and pads
The size tells you which kind a row is. Two dimensions, or a size ending in “cont.”, is a strip footing (sometimes WF for wall footing): width × depth, running under a wall. Its length comes off the foundation plan, and its volume is length × width × depth. Three dimensions is a pad (spread or column footing): you count the marks on the plan, and each is length × width × depth.
Watch the order. Many schedules print length × width × depth, but some print width first, and some split the depth into its own column. When a pad is square the order does not matter; when it is not, check a detail.
Reading the reinforcing
- 15M @ 300 E.W. — 15M bars at 300 mm centres, each way: a mat in both directions.
- (4) #6 E.W. — four #6 bars in each direction, spaced equally across the pad.
- (3) 15M cont. — three bars running the full length of a strip footing, lapped where they join.
- T&B or top and bottom — the same bars in two layers.
For bars each way at a spacing, the count across one side is the side less the cover at both ends, divided by the spacing, plus one. For continuous bars, add the lap lengths the structural notes specify. The rebar weight calculator turns either into kilograms or pounds.
What else to check
- Top of footing elevations and step footings — a stepped strip adds concrete and forms at each step.
- Keyways and dowels — often in the general notes, not the schedule.
- Notes that apply to every row — concrete strength, cover, and bearing requirements.
- Code minimums — on Ontario Part 9 houses, compare strip footing widths against the Building Code table for the floors supported.
Doing it on the drawings
PreConstruct AI reads footing, pad, grade beam, pier, column and beam schedules from a drawing set's text — marks, sizes and reinforcing, metric or imperial — and shows each row with the sheet and the words it came from. Any row can become a concrete type with its sizes and bars, which you check before you use. It reads text: a schedule drawn as a picture, or one it does not recognise, gives nothing, and the sizes and reinforcing always come from the structural drawings.