According to Hawaii Building Code, what is the maximum allowable deflection for roof beams under design wind loads?
Correct Answer
D) L/240
Hawaii Building Code limits roof beam deflection to L/240 under design wind loads to maintain structural integrity during hurricane conditions.
Why This Is the Correct Answer
L/240 is the maximum allowable deflection for roof beams under design wind loads per Hawaii Building Code. This ratio means the beam can deflect no more than 1/240th of its span length. For example, a 20-foot (240-inch) beam can deflect no more than 1 inch. L/240 is the standard wind-load deflection limit for roof members in Hawaii, balancing structural performance with practical construction.
Why the Other Options Are Wrong
Option A: L/180
L/180 is a less restrictive deflection limit (more deflection allowed) used for some roof elements supporting non-plaster finishes. It is not the limit for roof beams under wind loads in Hawaii. Using L/180 would allow too much movement, risking damage to roofing materials and connections.
Option B: L/360
L/360 is a more restrictive deflection limit (less deflection allowed) typically applied to floor beams under live loads to prevent noticeable bounce, or to beams supporting plaster ceilings. Applying L/360 to roof beams under wind loads would be overly conservative and is not the Hawaii Building Code requirement for this specific condition.
Option C: L/300
L/300 falls between L/240 and L/360 but is not the Hawaii Building Code's prescribed limit for roof beams under wind loads. It may appear in other deflection contexts but is not the correct answer for this specific application.
Memory Technique
Use the mnemonic '360 for floors, 240 for roofs': floors must be stiffer (smaller deflection = higher denominator), roofs under wind get L/240. Think of it as floors needing to feel solid underfoot (L/360) while roof beams have slightly more flexibility (L/240) since you don't walk on them.
More Hawaii Questions
A concrete mix design for coastal construction specifies a water-cement ratio of 0.40. If 650 lbs of cement is used per cubic yard, how many gallons of water should be added?
A contractor is installing hurricane straps rated at 1,500 pounds each. If the calculated uplift force on a rafter is 3,200 pounds, how many straps are required with a 2.0 safety factor?
Hawaii Building Code requires special inspection for concrete placement in seismic design categories. What is the minimum frequency for concrete strength testing?
What is the maximum allowable deflection for roof rafters under design wind loads in Hawaii's hurricane zones?
Which roofing attachment method is specifically required in Hawaii's hurricane zones for asphalt shingles on residential construction?
A building in Maui requires hurricane straps rated for 175 mph winds. If each strap must resist 1,200 lbs of uplift force and you have 48 roof-to-wall connections, what is the total uplift resistance provided?
During construction of a beachfront property, you notice white crystalline deposits forming on the concrete surface. This indicates:
You discover expansive clay soil conditions during excavation for a residential foundation in Kona. The plasticity index is 28. What foundation system is most appropriate?
According to Hawaii building requirements, hurricane straps connecting roof trusses to wall plates must be rated for what minimum uplift force in high wind zones?
A concrete slab foundation in Hawaii requires a vapor barrier. Due to high humidity and frequent rainfall, what type of vapor barrier is most appropriate?
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
What is the minimum concrete cover required for reinforcing steel in concrete exposed to Hawaii's coastal environment?
Next Question
A building in Maui requires hurricane straps rated for 175 mph winds. If each strap must resist 1,200 lbs of uplift force and you have 48 roof-to-wall connections, what is the total uplift resistance provided?