A floor framing plan packs a lot of structure into a small drawing, and it does so with a shared visual language. Once you can read the symbols — the arrows, line weights, callouts, and markers — the plan stops looking like a maze and starts reading like a set of instructions. This is a plain-language reference to the marks you will see most often.

If you are new to the document itself, start with what a floor framing plan is and come back here for the legend.

A legend of common framing plan symbolsJoists (span + spacing)Beam / headerBearing wallColumnOpeningA legend of common framing plan symbols

Joists and span direction

Joists are the repetitive floor members, and the plan has to communicate two things about them: which way they run and how far apart they sit.

  • Span direction is shown either by drawing the joists as a field of evenly spaced parallel lines, or by a single span arrow with a label. The direction matters — joists bear on the walls at each end of the run.
  • On-centre spacing is the distance from the centre of one joist to the next, written as something like @ 450 or @ 16" o.c. Tighter spacing generally means a stiffer floor for the same span.
  • Member callout identifies the joist type, for example J1. A schedule elsewhere on the sheet expands J1 into an actual size and material.

Beams and headers

Where joists stop — at an opening, a change of direction, or a long span — a larger member gathers their load.

  • Beams are drawn as a heavier line beneath or across the joist field, with a callout such as B1.
  • Headers (or trimmers) frame the edges of an opening, carrying the joists that were interrupted.
  • Member size callouts describe the section. A label like 2/240×45 means two 240×45 pieces laminated together. LVL or similar notes the material.

Bearing walls

Not every wall holds the floor up. The plan distinguishes load-bearing walls — the ones joists and beams actually rest on — from non-structural partitions.

Conventions vary: a heavier line weight, a hatch, a dedicated note, or a colour. In Framing Plan the bearing walls are drawn in red, and they default to the walls the joists span onto, so it is immediately clear where the load comes down. You can override the defaults when the design calls for it.

Openings

Any hole in the floor — a stair well, a duct chase, a hatch — interrupts the joist field and needs framing around it.

  • The opening is drawn as a gap or a marked rectangle in the floor.
  • The joists that would have crossed it are cut and carried by headers on each side.
  • Doors and windows in the walls are marked on the relevant wall with a type and width, and on a good plan they sit on their own layer so they can be exported cleanly.

Columns and the structural grid

On larger or multi-bay layouts, a structural grid sets out where loads come down.

  • Grid lines are the setting-out lines (often dashed) that establish bays and column positions.
  • Columns appear as small filled or outlined squares/circles at grid intersections.
  • Grid references (A, B, C / 1, 2, 3) let everyone refer to the same point unambiguously.

Dimensions and annotations

Finally, the marks that make the plan buildable:

  • Dimensions give the real-world distances — overall sizes, bay widths, opening offsets.
  • Annotations and notes carry spacing, member references, and instructions.
  • A title block records the project, drawing name, date, and — on preliminary work — a "not for construction" note.

Reading a callout end to end

Put it together with one label: J1 @ 450, sitting beside a span arrow, with the two walls at the ends of the run drawn in red.

That reads as: joist type J1, spaced 450 mm on centre, running in the arrow's direction, bearing on the two highlighted walls. The schedule turns J1 into a size. One short label, a direction, and a colour — and the whole structural intent of that room is on the page.

Put the symbols to work

The fastest way to internalise framing symbols is to place them yourself. In Framing Plan, the left palette holds structural symbols, openings, loads, and annotations — drag them onto the plan, and the joists, beams, and bearing walls are generated with the right conventions automatically. Open the framing studio to try it, then see how to draft a preliminary floor framing plan for the full workflow.