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Pre-cast Concrete Foundation and Wall Panel
Pre-cast Concrete Foundation and Wall Panel
Pre-cast concrete foundation and wall panels can take many forms. Some
consist of steel-reinforced concrete ribs that run vertically and
horizontally in the panels. Others are solid pre-cast concrete panels.
Panels are precast and cured in a controlled factory environment so
weather delays can be avoided. A typical panelized foundation can be
erected in four to five hours, without the need to place concrete on
site for the foundation. The result is a foundation that can be
installed in any climate zone in one sixth of the time needed for a
formed concrete wall.
Details
Some manufacturers cast the concrete against foam insulation that
provides the form during manufacture and added R-value in the wall.
Panels range in size from 2'-12' in width by 8' - 12' in height and are
typically installed with a crane on top of 4" to 6" of compacted stone.
The stone facilitates sub-slab drainage and adequately carries and
transfers the load from the foundation wall. Panel connections consist
of bolts and sealant. The foundation can be backfilled as soon as it is
braced per manufacturer's specifications.
The controlled temperature of the processing plant allows the
manufacturer to work with concrete admixtures that focus on ultimate
strength rather than cure time and temperature. Manufacturers are able
to produce mixes that harden to 5,000 psi, which is stronger than
concrete block or concrete walls formed and cast in the field. Better
control of the concrete mixture and curing environment allows the use
of low water/cement ratios that results in a dense material that
prevents water penetration.
Installation
Installers should be experienced with assembling prefabricated
foundation panels. In fact, some companies only allow certified
installers to deliver and erect their systems. Once panels are erected,
sealed, and bolted together, the basement slab can be poured. Floor
joists above the foundation are conventionally installed and provide
some of the bracing for the foundation walls. Once braced by the slab
and floor system, backfilling against the walls can take place.
Benefits/Costs
Priced in the $55 - $65 range per linear foot of wall, pre=cast systems
are competitive with other foundation walls, particularly when costs
are examined as an assembly that includes footings and sub-slab
drainage. Pre-cast walls can be installed quickly in any weather.
Because the concrete is cured in the factory, pre-cast foundations can
be backfilled as soon as the slab is placed and first floor bracing is
in place, enhancing jobsite safety and site accessibility.
Limitations
Door and window openings, steel beam pockets, and brick ledges must be
cast into the panels, so orders must be customized. The wall sub-base
must be compacted and leveled, similar to precision required of
footings. Use of pre-cast panels should be submitted for approval by
the building official at time of building permit application.
Code/Regulatory
The 2003 version of the International Residential Code (IRC) recognizes
precast concrete foundation walls. Designs that utilize pre-cast walls
should be submitted for pre-approval with other architectural details
at building permit application.
Disclaimer: The
information on the system, product or material presented herein is
provided for informational purposes only. Curtesy of the U.S.
Department of Housing and Urban Development (HUD/FHA),
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