Installation Instructions

32 SABIC Innovative Plastics
Wind and Snow Loading
Dynamic Wind Pressure
The wind speed is used to determine the actual loading
upon the glazing panels. In mathematical terms, the
pressure loading is calculated by multiplying the square
of the design wind speed by 0.613.
q = KV2
where q = dynamic wind pressure in N/m
2
K = 0.613
V = design wind speed in metres/second
Table 16: Values of q in SI units (N/m
2
)
wind
speed m/s
wind
pressure N/m
2
10 61
15 138
20 245
25 383
30 552
35 751
40 981
45 1240
50 1530
55 1850
60 2210
65 2590
For glazing projects with an unusual loading condition, please contact
your local SABIC Innovative Plastics Sales Ofce
The Beaufort scale transforms wind into static pressure:
WIND light moderate strong storm
Speed (km/h) 20 40-60 80-100 120-140
Speed (m/sec) 6 11-17 22-28 33-39
Static pressure (N/m
2
) 20 80-170 300-480 680-950
Pressure Coefficient
To allow for local uctuations in the acceleration/
deceleration of the wind by building or glazing geometry,
it is necessary to include an appropriate pressure
coefcient.
Determine pressure coefcients requires knowledge of:
• Form and type of building
• Height of glazing
• Shape of glazing e.g.
- Flat vertical
- Inclined roong
- Curved glazing
The wind loading is obtained by multiplying the
dynamic wind pressure by the pressure coefcient.
The total wind loading can be positive indicated a wind
pressure force or negative indicating a wind suction
load. Detailed pressure coefcient values can be found
in the appropriate national building norms.
Snow Loading
Snow loading on roof glazing can be considered
equivalent to a vertically, uniformly distributed load,
acting per m
2
of the horizontal projection of the glazing.
A roof made of Lexan Thermoclear sheet does not
permit immediate melting of the snow, due to its
excellent thermal insulation, and therefor the load
produced by the snow must be carefully taken into
consideration.
Snow-indicative weights per centimetre of height
fresh snowfall - 0.8-1.9 kg/m
2
per cmh.
wet snowfall - 2-8 kg/m
2
per cmh.
Snow loading factors can be obtained from the
appropriate local building norm.
Computer Aided sheet Engineering
A computer aided design programme has been
developed especially for large glazing projects, or
projects with an uncommon shape or unusual loading
conditions. The programme creates the nite element
model of a particular glazing design, applies the specied
loads and edge conditions and runs the deection
analysis. Consult your nearest SABIC Innovative Plastics
Technical Service Centre for further advice.
Table 16a:
Height of
Building ft
wind speed
ft/s
wind pressure
lb/ft²
0 – 26 93 10,4
26 – 66 117 16,7
66 – 328 138 23,0
> 328 150 26,1