Concrete (C-8) · Lesson 2 of 7

Sizing a Footing from the CRC Tables

"Sizing a Footing from the CRC Tables" is lesson 2 of 7 in the Concrete (C-8) Learning Hub. It opens with "Start With the Soil: Presumptive Bearing Values" and works through 5 short steps, then a worked example you can check yourself against.

Open the free trialSee pricing

One-time purchase, no subscription. Law & Business included.

Steps in this lesson

  1. Start With the Soil: Presumptive Bearing Values
  2. Know What the Footing Tables Are For
  3. Read the Row and the Column
  4. Adjust for Building Width and Between Soil Values
  5. Check the Projection, Then Build It

The worked example in the course applies this lesson to a realistic job in 5 steps, from "Find the soil value" through "Check the projection".

What you'll be able to do

  • Explain the main idea of "Sizing a Footing from the CRC Tables" in plain language you can use on the exam.
  • Apply this step with confidence: "Read the Row and the Column".
  • Apply this step with confidence: "Adjust for Building Width and Between Soil Values".
  • Apply this step with confidence: "Check the Projection, Then Build It".
  • Test yourself on the worked example and the quick-check quiz inside the classroom.
SIZING A FOOTING FROM THE CRC TABLES2025 CRC R401.4.1(1), R403.1.1 and Table R403.1(1)FOOTING SECTION (NOT TO SCALE)stemwallconcrete footingPW = 19 inT = 8 inP = 6.5 ineach sideTABLE LOOKUP (2025 CRC)Soil: clay (CL) = 1,500 psfTable R401.4.1(1)2-story, crawl space, 20 psf roof liveload, 1,500 psf column: 15 x 6 inTable R403.1(1)Building 40 ft wide: (40 - 32) / 4 = 2 stepsWidth +2 x 2 in = +4 in: 15 + 4 = 19 inDepth +2 x 1 in = +2 in: 6 + 2 = 8 inTable R403.1(1) notes c and dStem 6 in: P = (19 - 6) / 2 = 6.5 in2 in ≤ 6.5 in ≤ 8 in (T): OKR403.1.1 projection ruleFooting 19 in wide x 8 in thickSame house, 32 ft wide, soil 1,750 psf: 13.5 x 6 in (interpolated)Interpolate between soil columns (note a); never extrapolateSource: 2025 California Residential Code R401.4.1(1), R403.1(1) notes a-d, R403.1.1CC
The diagram for this lesson, exactly as it appears in the Learning Hub.

The first steps of this lesson

Step 1: Start With the Soil: Presumptive Bearing Values

2025 CRC R401.4.1 says that, in lieu of a full geotechnical evaluation, the load-bearing values in Table R401.4.1(1) are assumed. The table prints crystalline bedrock 12,000 psf; sedimentary and foliated rock 4,000 psf; sandy gravel and/or gravel (GW and GP) 3,000 psf; sand, silty sand, clayey sand, silty gravel and clayey gravel (SW, SP, SM, SC, GM, GC) 2,000 psf; and clay, sandy clay, silty clay, clayey silt, silt and sandy silty clay (CL, ML, MH, CH) 1,500 psf. Footnote b adds that if the building official expects in-place soil below 1,500 psf, a soils investigation sets the value.

Step 2: Know What the Footing Tables Are For

R403.1.1 sends you to Tables R403.1(1) through R403.1(3) for the minimum width W and thickness T of concrete footings, but never less than 12 inches wide and 6 inches deep. Table R403.1(1) covers light-frame construction; Table R403.1(2) covers light-frame with brick veneer or lath and plaster; Table R403.1(3) covers cast-in-place concrete or partially grouted masonry wall construction. The width is picked by the soil bearing value from Table R401.4.1(1), and R403.1 requires the footing to sit on undisturbed natural soil or engineered fill.

The remaining 3 steps, the worked example and the quiz are in the course. This is a preview. The full lesson, with the step-by-step explanations, a worked example and a quick-check quiz, is inside the classroom.

More lessons for this trade

Browse all lesson previews

Ready to practice for real?

Try the real classroom free, no sign-up, or get the full course for your trade.

Open the free trialSee pricing

Independent exam preparation. Contractors Classroom is not affiliated with the Contractors State License Board, and no course can guarantee a passing result.