Building Your Shelter
FEMA 320, Second
edition - 7.7 MB
Your builder/contractor can use the design drawings in this booklet to build a
shelter for any of the wind zones shown on the map. The design drawings
provided include the details for building five types of shelters: concrete,
concrete masonry, wood-frame, lean-to, and in-ground. Each of these
alternatives is expected to perform equally well in resisting material fatigue
and connection failures caused by extreme winds.
The materials and connections were chosen for their "ultimate strength," which
means that the materials are expected to resist the loads imposed on them until
they or the connections between them fail. The forces of extreme winds may
cause cracks or other signs of stress in the materials or connections, and they
may cause materials or connections to yield. However, the intent of the designs
is not to produce a shelter that will always remain completely undamaged, but
rather a shelter that will enable its occupants to survive an extreme windstorm
with little or no injury. The shelter itself may need to be extensively
repaired or completely replaced after an extreme wind event.
The shelter size and materials specified in the drawings are based on
principles and practices used by structural engineering professionals and the
results of extensive testing for effects of missile impact. Before increasing
the shelter size or using material types, sizes, or spacings other than those
specified in the drawings, review the changes with a licensed professional
structural engineer.
The information in this section includes the following:
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design drawings and details for shelters in basements, above the ground, and in
the ground
-
designs for both slab-on-grade and crawlspace foundations
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general design notes and fastener and hardware schedules
-
materials lists with quantities and specifications
The Wind Engineering Research Center at Texas Tech University has been involved
in shelter design for many years. If you or your builder/contractor have
questions about the design drawings in this booklet, call the Wind Engineering
Research Center at
(888) 946-3287, ext. 336 for technical
guidance.
Download FEMA 320 Plans