What is the maximum deflection allowed for a floor joist with a 16-foot span under live load according to CBC?
Correct Answer
D) L/360 = 0.53 inches
CBC limits floor joist deflection to L/360 under live load. For 16 feet span: 16 × 12 ÷ 360 = 0.53 inches maximum deflection.
Why This Is the Correct Answer
CBC follows IBC/ASCE 7 deflection limits, which set the maximum live-load deflection for floor members at L/360. For a 16-foot (192-inch) span: 192 ÷ 360 = 0.533 inches, which rounds to 0.53 inches. The L/360 limit is the standard for floor systems to prevent perceptible bounce and protect finish materials.
Why the Other Options Are Wrong
Option A: L/480 = 0.4 inches
L/480 = 0.4 inches is a more restrictive limit sometimes applied to ceilings with brittle finishes (e.g., plaster) or to members supporting sensitive equipment. It is not the standard live-load limit for floor joists.
Option B: L/240 = 0.8 inches
L/240 = 0.8 inches is the limit for total load (dead + live) deflection on roof members, not the live-load limit for floors. Using this less restrictive limit would allow excessive floor springiness.
Option C: L/300 = 0.64 inches
L/300 = 0.64 inches is not a standard CBC deflection limit for floor live loads. It appears in some specialty applications but is not the correct value for this scenario.
Memory Technique
Memorize the key ratios: Floor Live Load = L/360. Roof Live Load = L/240. Total Load floors = L/240. Think '360 degrees in a circle = a solid, bounce-free floor.'
More California Questions
A contractor is installing shear walls in a residence located in Seismic Design Category D. The engineer's plans call for 15/32-inch structural sheathing with 8d nails at 6 inches on center at panel edges. The contractor wants to substitute 7/16-inch OSB with the same nailing. Is this substitution acceptable?
You are reviewing plans for a mixed-use building where the ground floor will house a restaurant with commercial kitchen equipment. The architect has specified standard residential electrical requirements throughout. What Title 24 compliance issue should you identify?
According to CBC seismic provisions, what is the concept behind the 'strong column, weak beam' design philosophy?
A residence in California has 2,800 sq ft of conditioned space. The HVAC system efficiency is 16 SEER. What is the approximate Title 24 compliance margin compared to the minimum 14 SEER requirement?
You're constructing a foundation on liquefiable soils identified in a California coastal area. The geotechnical report recommends deep foundations. Which option is most commonly specified?
A contractor is installing a heat recovery ventilation (HRV) system to comply with Title 24. The system serves a 2,000 sq ft house with 3 bedrooms. What is the minimum required ventilation rate?
During construction of a basement in sandy soil conditions, you encounter groundwater at 4 feet below grade. The basement extends 8 feet below grade. What is the critical design consideration per CBC?
During a seismic retrofit project, you discover that existing concrete has a compressive strength of 2,200 psi. The engineer specifies new anchor bolts that require 2,500 psi minimum concrete strength. What is the most appropriate action?
What is the maximum allowable notch depth in a 2x10 floor joist per CBC requirements?
You're reviewing plans for a wood-framed structure in seismic design category D. The project calls for a shear wall with 15/32-inch structural sheathing and 8d nails spaced 6 inches on center at panel edges. What is the allowable shear value per the CBC?
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