How To Build A Spray-In-Place Concrete Fence - Monolithic

Well laid-out plan for a zigzag fence (above). It would be even better if the ends of the fence
by the driveway had doubled fence posts, a box (see drawing page 5), or a turn to give greater
stability and a more finished look.
contraction is more severe especially
for long straight runs of fence. Twice
as many posts need to be installed
because they are all that hold it up.
The posts need to be a little larger in
diameter and be deeper in depth.
Consider wind pressure: A wind
blowing 100 miles per hour against
a vertical fence will push with 50
pounds per square foot against the
fence. If the fence is six feet tall that
means there is 300 pounds of push
per foot down the length of the fence.
The taller part of the fence has a
lever action against the ground which
increases its propensity to roll over.
In other words, the taller the post
the more leverage it exerts. This 300
pound push is considered in average
three feet above the ground. If the
posts are eight feet apart and we have
an average of 300 pounds of push,
that equals 2400 pounds of push on
one fence post.
That fence post must be able to
resist snapping off at ground level and
the post hole must resist enlarging to
prevent turn over at ground level. If
the hole starts to enlarge even a little
bit, the fence tends to pound the hole
larger and larger as the wind hits it
and backs off over and over again. A
fence that can withstand being tipped
over from a one-time push may fail to
the buffeting of an intermittent wind.
It is therefore very important that the
post be larger in diameter and set deep
enough to withstand this turn over at
the ground line.
The Zigzag Fence — Advantages
The zigzag fence is much stronger
and more durable than a straight
fence. It will stand up to expansive
soils, wind loads and expansion and
contraction much better than a straight
fence. It proves interesting by being
Note the forms set up for shotcreting (left).
This four-foot high fence is zigzagged one
foot off center each way. Surprisingly, when
completed one hardly notices the zigzags
in this fence. The posts have already been
poured. The bracing must resist wind until
the fence is sprayed and solid.
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