According to the USBC, what is the maximum allowable deflection for a residential floor joist under live load?
Correct Answer
C) L/360
The Virginia Uniform Statewide Building Code limits residential floor joist deflection to L/360 under live load to ensure structural integrity and minimize vibration.
Why This Is the Correct Answer
The Virginia USBC (consistent with the International Residential Code it is based on) limits residential floor joist deflection to L/360 under live load. This ratio means the joist can deflect no more than its span length divided by 360. L/360 is the standard that prevents perceptible bounce and protects finishes like tile and drywall from cracking.
Why the Other Options Are Wrong
Option A: L/480
L/480 is incorrect for live load floor joists. L/480 is a stricter limit applied to rafters supporting plaster ceilings or other more sensitive assemblies. Using L/480 for floor joists represents an overly conservative (and incorrect) application of deflection limits.
Option B: L/300
L/300 is incorrect. L/300 is a less stringent deflection limit sometimes applied to roof rafters under live load (not floor joists). Applying L/300 to floors would allow more deflection than the code permits, potentially resulting in bouncy floors and cracked finishes.
Option D: L/240
L/240 is incorrect. L/240 is the deflection limit for floor joists under total load (live + dead), not live load alone. The live-load-only limit for floor joists is the more restrictive L/360. Confusing total load and live load deflection limits is a common exam error.
Memory Technique
L/360 = Live Load Floor Standard. The number 360 has a 6 in it — think '6-pack of floors' for live loads. Or: a full circle is 360 degrees, and your floor should feel solid all the way around — L/360 keeps it stiff under live load.
More Virginia Questions
Under Virginia law (Title 54.1), what is the minimum net worth requirement for a Class A contractor license?
A Virginia contractor fails to pay a subcontractor $18,500 for completed work. Under Virginia mechanics lien law, within how many days must the subcontractor file a memorandum of lien to preserve their lien rights?
A Virginia contractor employs 8 workers with a total annual payroll of $420,000. Using the standard construction rate of $8.50 per $100 of payroll, what is the annual workers' compensation premium?
A Virginia contractor fails to pay subcontractors on a $180,000 project. Under Virginia mechanics lien law, what is the maximum time period a subcontractor has to file a mechanics lien after last furnishing labor or materials?
Under Virginia contractor law, what happens to a contractor's license if they fail to maintain required insurance coverage?
A contractor fails to pay a subcontractor and the subcontractor files a mechanics lien. Under Virginia law, within how many days must the general contractor post a bond to release the lien from the property?
A Class B contractor in Virginia completed $850,000 worth of work in the current license period and has contracts totaling $1,200,000 for the next period. What action must the contractor take?
A homeowner hired an unlicensed contractor for a $45,000 kitchen renovation. Under Virginia law, what remedy is available to the homeowner?
Calculate the required bond amount for a Virginia Class A contractor with average annual gross receipts of $2,800,000 over the past three years.
A Class C contractor in Virginia wants to install a residential HVAC system valued at $12,000. The contractor's specialty classification is electrical work. What must the contractor do to legally perform this work?
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 Class B contractor in Virginia wants to bid on a $175,000 commercial renovation project. According to Virginia contractor law, what action must the contractor take?
Next Question
Under Virginia Code Title 54.1, what is the minimum net worth requirement for a Class A contractor license?