There are several types of
foundations used in
residential construction but
all have one important
requirement, the foundation
and connections to the walls
and floors must be strong
enough not only to support
the weight of the house and
its contents but to prevent
the home from being blown
away by high winds.
Common Foundation Types
The two most common types of
foundations are monolithic
slab-on-grade and stemwall
foundations.
A slab on grade foundation
is a single, continuous
layer of concrete that sits
directly on the ground. The
concrete slab is the floor
system. A slab-on-grade
foundation should be
reinforced with welded wire
fabric and have longitudinal
reinforcement in the footing
or turndown.
Construction Techniques
There are many construction
techniques for anchoring the
exterior walls to the
foundation.
For wood-framed
construction, the bottom
plate of the wall should be
anchored into the slab with
anchor bolts and washers.
The bottom plate should be
securely connected to the
wall studs above by using
approved metal clips or
straps.
For concrete masonry
construction, vertical
reinforcement in a
continuously grouted cell
should extend from the wall
above and be embedded in the
concrete footing below with
a standard hook.
Stemwalls
A stemwall is a concrete
block or brick wall used on
top of the footer for off
grade houses where the
ground slopes from one side
to the other.
Stemwalls can support both
concrete slabs and
wood-framed floors.
Stemwalls should have
vertical reinforcement in a
continuously grouted cell
extending from the concrete
masonry wall and embedded in
the concrete footing with a
standard hook.
The concrete footing should
also have longitudinal
reinforcement.
Anchorage for an exterior
wall to a stemwall
foundation is similar to
anchoring to a
slab-on-grade.
Metal connectors and anchor
bolts must be used to
securely connect the walls
to the foundation and give
your home the required
resistance to the forces
created by extreme winds.
Visit
www.flash.org or call
toll-free (877) 221-SAFE for
more information about
protecting your home from
disaster.
Copyright 2004 Federal
Alliance for Safe Homes
FLASH, Inc. All rights
reserved. |
