Tornadoes
The speeds of windborne debris and the peak wind
pressures in tornadoes can, in many cases, be
much higher than those specified in ASTM E1996.
FEMA document specifies a 15lb. wood 2x4 fired
at 100 mph. This has approximately 14 times the
energy of the large missile used in wind zone 4
of ASTM E1996. Glass and glazing designed
and tested, to resist hurricane-impact and cyclic
pressure loads can, however give considerable
resistance and protection against lower categories
of tornadoes.
