A contractor discovers that the soil bearing capacity at a job site is 1,500 psf. The house will impose a total load of 45,000 pounds on a continuous footing. What is the minimum footing width required?
Correct Answer
D) 30 inches
Required footing area = 45,000 lbs ÷ 1,500 psf = 30 sq ft per linear foot, so 30 inches wide minimum.
Why This Is the Correct Answer
The calculation: Required footing area = Total load ÷ Soil bearing capacity = 45,000 lbs ÷ 1,500 psf = 30 square feet. For a continuous footing, this equals 30 inches of width per linear foot (since 30 sq ft per linear foot expressed as inches = 30 inches). The minimum footing width is 30 inches.
Why the Other Options Are Wrong
Option A: 42 inches
42 inches would result in an area of 42 sq ft per linear foot, far exceeding the 30 sq ft needed. This over-engineers the footing and is not the minimum required width.
Option B: 36 inches
36 inches provides 36 sq ft per linear foot of support capacity, which exceeds the 30 sq ft minimum. It is a valid width but not the minimum — the exam asks for the minimum.
Option C: 24 inches
24 inches would provide only 24 sq ft per linear foot of bearing area (24 in = 2 ft; 2 ft × 1,500 psf = 3,000 lbs/ft), which is insufficient. The footing would be undersized and could fail under the imposed load.
Memory Technique
Formula: Width (ft) = Load (lbs) ÷ Bearing Capacity (psf). Then convert feet to inches (× 12). Here: 45,000 ÷ 1,500 = 30 ft² per lineal foot → 30 inches wide. The numbers work out cleanly — 30 feet squared equals 30 inches because 30 ft² ÷ 1 linear ft = 30 ft = 30 inches.
More mi-builder Questions
A residential foundation wall in Michigan is 8 feet high with 2 feet above grade. The backfill exerts lateral pressure of 30 psf per foot of depth. What is the maximum lateral pressure at the bottom of the foundation wall?
A builder discovers that the electrical service entrance was installed without proper permits. According to Michigan law, what is the most appropriate next step?
What is the maximum allowable span for a 2x8 floor joist (Grade 2 Douglas Fir) at 16" O.C. with 40 psf live load and 10 psf dead load according to Michigan Building Code span tables?
According to Michigan Building Code, what is the maximum height of a wood-framed bearing wall using 2x4 studs with standard construction?
A homeowner requests to convert a bedroom into a bathroom on the second floor. What is the primary Michigan code concern the builder must address?
According to Michigan plumbing regulations, what is the minimum pipe size required for a water service line serving a single-family residence?
A contractor is building a basement foundation wall that is 8 feet high and will retain 6 feet of soil. What is the minimum wall thickness required by the Michigan Building Code for poured concrete?
A homeowner wants to install a gas fireplace in their living room. The contractor notices the existing gas line is 1/2 inch black iron pipe. For a 40,000 BTU fireplace with a 25-foot run, is this pipe size adequate according to Michigan gas code?
During a framing inspection, the building official notes that the contractor used 2x4 studs at 24 inches on center for an exterior wall. According to Michigan Building Code, what is the maximum wall height allowed for this configuration?
A contractor is installing a beam to support floor joists. The beam must carry a total load of 8,000 pounds over a 12-foot span. If the allowable fiber stress for the lumber grade is 1,200 psi, what is the minimum required section modulus?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass
Related Study Resources
Previous Question
A contractor is building a house with a crawl space. According to Michigan Building Code, what is the minimum height requirement for crawl spaces?
Next Question
A builder is installing a beam to support a 20-foot span with a total load of 800 pounds per linear foot. If using a steel beam with an allowable bending stress of 24,000 psi, what is the minimum required section modulus?