ROOF WIND PRESSURES FOR DUOPITCH ROOF PERMEABLE BUILDINGS

Roofs of buildings have been observed to fail in wind
storms. Traditionally in Malaysia, roof pressures are determined
based on BS 6399-2 or MS1553. This paper presents the analysis
of wind code provisions in the four major codes (BS 6399-2, MS
1553, EC1-1-4 and IS 875-3), including basic wind speeds, terrain
categories and terrain multipliers, and general and local wind
pressures on duo-sloped roof permeable buildings in Malaysia.
For numerical comparison, the maximum wind speed
recommended in MS 1553 namely 33.5 m/s has been used. The
major differences in the codes include averaging time for wind
speed, reference height of buildings, values of internal and
external pressure coefficients. Eurocodes has been included in the
context of its introduction in Malaysia, and IS 875-3 is another
code from the tropical zone namely India. The study examines
the conservativeness or not of the codes if used in the Malaysian
context, even though they have been developed for a different
wind climate and region. The results of the study are reported.