How to Set Concrete Footings
How to excavate, form, and pour strip footings and isolated pad footings that support walls, columns, and structural loads.
Step-by-Step
- 1
Locate footing positions
Establish footing centerlines from the building layout using batter boards and string lines. Verify dimensions and diagonal measurements for square. Mark the footing edges with marking paint or chalk.
- 2
Excavate to bearing depth
Dig to undisturbed soil below the frost line. In most of the US, this is 12–48 inches depending on climate zone. The bottom of the excavation must be undisturbed — any loosened soil must be compacted before placing concrete.
- 3
Verify bearing conditions
The soil at the bottom of the excavation should be firm and undisturbed. If you encounter soft spots, fill them with lean concrete (mud mat) or compact granular fill and get engineer approval. Never pour on soft or wet soil.
- 4
Set forms for above-grade footings
If the footing extends above grade, set form lumber aligned to the string lines. Check forms for level and secure with stakes. For round piers, use fiber tube forms cut to height.
- 5
Place rebar
Install rebar per the structural drawings. Maintain 3-inch cover from all earth faces and 1.5 inches from formed faces. Tie intersections. Verify rebar size and spacing matches the drawings before calling for concrete.
- 6
Place and consolidate concrete
Place concrete in continuous lifts. Use a vibrator to consolidate — work the vibrator in and out slowly, overlapping insertion points by 6 inches. Never drag or rake concrete horizontally more than 5 feet.
- 7
Strike off and level the top
Strike the top of the footing level with a screed or strike-off board. Embed anchor bolts or hold-down hardware while the concrete is still workable, using a template to ensure correct positioning.
- 8
Cure and protect
Cover footings with poly sheeting to retain moisture. In cold weather, use insulating blankets. Do not allow traffic or construction loads on footings for at least 7 days.
Pro Tips
- → Set anchor bolts with a template cut from plywood — freehand setting always drifts.
- → Photograph all rebar placement before the pour — it's your documentation if questions arise.
- → Pour footings continuously. A cold joint at mid-height is a structural deficiency.
- → Keep a 2-foot stake next to each anchor bolt to mark its location if you need to find it after backfill.
Watch Out
- ! Footings must bear on undisturbed native soil or engineered fill — never on topsoil or fill that hasn't been compacted.
- ! Do not backfill around footings until the concrete has reached adequate strength — minimum 3 days, preferably 7.