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Commonly used methods
- Method 1: Put up 2X4 strongbacks
and kickers every few feet
- Method 2: Use prefab scaffold/bracing
system
- Method 3: Construct own
combined scaffold/bracing from 2X lumber
Comments:
Rick Hansen- Reddi-Form Northwest
Phone: 406-587-4903
Email: reddiformn@aol.com
On Reddi-Form we use a 3/16" wire needle that uses tie-wire as thread
to clamp 2x4's on either side of the wall (3 places on a 10' wall
is sufficient). A diagonal brace to an exterior stake eliminates any
interior interference with rolling a scaffold. Other than walls over
25" long or where we encounter a walls seam no other bracing is required
with our system.
Floating is not a problem with Reddi-Form. But when using
a pump truck without sufficient hose reduction and/or elbows, the
rebound of concrete off of concrete below and into the eps web can
cause the block to be BUMPED upward. Concrete truck chutes, or workers
bumping the forms can also cause this. A small spot of foam from a
gun here and there eliminates any of these possibilities. Try it and
you'll like it, but if you glue the entire wall together on the way
up you may find that you have glued a stubborn wave or tilt into your
wall.
Peter Juen- SE Florida
Polysteel Inc.
Phone: 561-225-5404
Email: seflpolyst@aol.com
We align the top of the wall by checking it against a stringline
we run from corner to corner. If needed, we screw a long drywall
channel horizontally to the furring strips of the top forms or to
the tops of the vertical window and corner braces. this really straightens
the top of the wall and provides a grab rail for the pour, which
we usually do with a rolling scaffolding. (There are no basements
in south florida, everything is slab on grade.) We also try to use
up all the smaller cut pieces at the top of the wall (less pressure).
This helps keep them straight and braced for the pour also. Some
builders make ladders for the top of the wall out of 2x4's which
are then resting and nailed to the vertical braces. With this method
you can walk and pour from the top of the wall. When a 2nd story
is needed, the ledger of the floor system, complete with anchor
bolts and joistbuckets can be attached to the furring strips before
the pour and serve as an alignment tool as well.
Norman Williams- GREENBLOCK METRO-PLEX
Phone: (972) 291-5995
Email: will913@flash.net
When you put bracing/scaffolding systems on flat block walls
sometimes the forms appear to float, however this is not what is
happening. The bottom courses of block compress under the weight
of the concrete. The top 2 courses do not have as much downward
presure on them. But sometimes the brace has the upper courses in
a bind and will not let them go down. So the bottom courses are
pressed down and the top ones held up, creating gaps at the seams
in between and making it appear the top blocks are floating.
With the Wall Alignment and Scaffolding System (WASS) this happens
if the hat brackets are bent or the bracing lumber is warped. With
the AAB bracing system this happens when the attachment screws are
tightened all the way into the block. These are the only alignment
systems we have used so I'm unable to comment on what causes this
with other systems.
EDITOR'S NOTE: The bracing systems described above are used
primarily with flat ICF systems. When using grid or post-and-beam
systems, concrete actually flows under foam webs. According to some
of the manufacturers, this can lead to the forms lifting up a little--"floating"
in the concrete. So for these systems the problem may actually not
be caused by faulty bracing. The usual solutions for this are gluing
the blocks, tying down the rebar, or weighting down the forms on
top. In theory, flat systems should not float because there is no
place that concrete gets "under" the foam.
Many thanks to Norm Williams for explaining how faulty bracing attachment
can cause forms to appear to float and make problems.
Rob Dykeman- ICF Information
Phone: 800-857-2324
Email: dykeman@sugar-river.net
I brace with a vertical 2x4 laid up against the wall and attached
to it every few feet, with a kicker and turnbuckle on the end of
the turnbuckle. Then I can adjust the turnbuckles to plumb the wall.
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