Fence Posts

The fence post is the foundation of
the fence, so its importance cannot
be overemphasized. The common element
in virtually all successful horse
fences is a wooden post. Setting posts
represents the hardest work and the
most time-consuming part of fence
building and is absolutely the most
critical to the long-term success of
the fence.

Driven posts are more rigid and
therefore recommended over handset
posts or those set in predrilled
holes. Driven posts are pounded into
the ground through a combination
of weight and impact by specialized
equipment. The principle behind
driven posts that makes them so
secure is that the displaced soil is
highly compacted around the post,
resisting post movement. Even for
do-it-yourself projects, you should
contract the job of driving posts. Postdriver
equipment is nearly impossible
to rent due to liability concerns.
Under some dry, hard, or rocky soil
conditions, a small-bore hole will be
necessary for driven posts.

Wood is recommended for all
horse fence posts. The best buy is a
pressure-treated post from a reputable
dealer. The preservative must be
properly applied to be fully effective.
Initially, treated posts are more expensive
than untreated ones, but they
last four times as long as untreated
ones. Depending on soil conditions
and preservative treatment quality,
a pressure-treated post can last 10 to
25 years.

Suitable wooden fence posts are
similar for board and mesh fences.
High-tensile wire and other strandtype
fences require similar posts, but
distances between posts are often
much longer than for board or mesh
fence. Post distance on high-tensile
wire fence depends on wind influences
and topography. Round wood
posts are stronger and accept more
uniform pressure treatment than
square posts of similar dimension.
Attachment of wooden rail boards to
round wood posts is improved when
one face of the post is flat.
Exceptions to wood posts are allowed
for horse-safe steel posts typically
used on chain link fences, pipe
posts from welded fences, and rigid
PVC fence post. Hollow posts require
top caps to cover the ragged top edge,
or should be designed that the top
fence rail covers the top of the post.
Recycled plastic, 4-inch-diameter solid
posts are suitable for horse fence, but
require a small-bore pilot hole before
driving. Metal and fiberglass T-posts
are slightly cheaper but pose a serious
risk of impalement and are not recommended.

They are also not strong
enough to withstand horse impact
without bending. With a plastic safety
cap installed on the top, T-posts may
be cautiously used in very large pastures
where horse contact is rare.
How deep to set the post for structural
stability varies considerably with
soil conditions. Soil characteristics
play a major role in determining the
longevity and maintenance requirements
of a fence. Some soils remain
wet and can quickly rot untreated
wooden posts. Posts in sandy or
chronically wet soil will need to be
set deeper and perhaps supported
by a collar of concrete casing. Other
soils tend to heave with frost and can
loosen posts that are not driven deep
enough. Fences under tension, such
as wire strand or mesh materials,
will require deeply set posts to offer
long-term resistance against tension.
A typical line post depth is 36 inches.
Corner and gateposts are required to
handle greater loads and are about
25% larger in diameter and are set
deeper, often to 48 inches.-