Question

For simply supported beams, the allowable deflection shall not exceed:

• A. 1/325 of span
• B. 1/350 of span
• C. 1/375 of span
• D. 1/400 of span

Answer 1

The correct option is B 1/350 of span

(b)
Clause 23.2 of IS 456 stipulates the limiting deflections under two heads as given below:

(a) Th maximum final deflection should not normally exceed span/250 due to all loads including the effects of temperature, creep & shrinkage & measured from the cast level of the supports of floors, roof & all other horizontal members.

(b) The maximum deflection should not normally exceed the lesser of span/350 or 20 mm including the effects of temperature, creep & shrinkage occuring after erection of partitions & application of finishes.