Grade Beam (GB) and Footing (F) Schedules Explained

GB1, F1, WF1 — these marks on commercial drawings reference concrete schedules, not steel. They're often grouped on the same sheet as the column and ledger schedules (commonly S008), which trips up takeoff software that assumes every mark is a steel reference.

Three concrete schedules you'll see on most commercial drawing sets:

GRADE BEAM (GB) SCHEDULE — concrete grade beams running between footings with rebar reinforcement
ISOLATED FOOTING (F) SCHEDULE — square or rectangular concrete footings under columns
CONTINUOUS FOOTING (WF) SCHEDULE — continuous concrete footings under load-bearing walls

These are NOT steel takeoff line items. They go to the concrete subcontractor. But on combined drawing sets they sit next to your column schedule and need to be filtered out cleanly.

What's in a GB Row

GRADE BEAM (GB) SCHEDULE
MARK    DIMENSIONS    TOP REINF       BOTTOM REINF    STIRRUPS
GB1     36" x 48"     9- #7           9- #7           #3 @ 12" O.C.

The dimensions are width × height of the concrete cross-section. The reinforcement is the rebar embedded in the beam (top and bottom reinforcement, plus stirrups for shear).

What's in an F Row

ISOLATED FOOTING (F) SCHEDULE
MARK    DEPTH    LENGTH    WIDTH    LONGITUDINAL     TRANSVERSE
F1      16"      6'-6"     6'-6"    8- #5 BOTTOM     8- #5 BOTTOM
F2      24"      7'-0"     7'-0"    9- #5 BOTTOM     9- #5 BOTTOM

Each footing is sized to support a column above. F-marks correlate one-to-one with SC-marks on the column schedule (often documented elsewhere in the drawing set as a "column-footing schedule" cross-reference).

How These Relate to Your Steel Takeoff

You typically don't include these in a steel BOM. But you do need to:

Recognize the marks (GB1, F1) as concrete references and exclude them from the steel count
Know which columns sit on which footings if you're providing structural breakdowns
Flag any combined schedules where steel and concrete are interleaved

Steelflo's schedule parsing reads these schedules but flags them as non-steel automatically — they appear as reviewable items with the concrete dimensions Gemini extracted, so you can confirm or break them out without losing the count.

FAQ

Q: Are GB and F schedules required on every drawing? On any building bigger than a small residential — yes, the engineer needs to specify foundation reinforcement somewhere. On small jobs they're sometimes inline notes on the foundation plan instead of a formal schedule.

Q: Should my takeoff software read these? Ideally yes, but only to recognize and SKIP them as steel members. Including concrete in a steel BOM corrupts the line items.

Q: What's the difference between F and WF? F (isolated) sits under a single column. WF (wall footing or continuous footing) runs continuously under a load-bearing wall.