Presumptive load-bearing values in IRC Table R401.4.1 assign 1,500 pounds per square foot to clay and 3,000 pounds per square foot to sandy gravel. For the same house load, how should the continuous footing width change if the soil is clay rather than sandy gravel?
- AThe clay footing must be about twice as wide because bearing pressure is half as large
- BThe clay footing may be half as wide because clay is more cohesive
- CFooting width is independent of soil type once the 12-inch minimum is met
- DClay requires a thicker footing but the same width as sandy gravel