Trre OnIGINAL HONAE WOOOWORKING RruN ... - Wood Tools

I lsefting Fence Posts
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Setting posts is one of those jobs where it really
pays to do it right the first time. It's not a com-
plex process, but a few common mistakes can
result in premature post failure and a heap of
extra work. Whether it's a single post for a
mailbox, or a dozen to hold up a long stretch of
fence, follow these simple steps and
you'll set posts that will still be stand-
ing straight and tall years from now.
CAN YOU DIG IT?
Probably the single biggest mistake
people nrake when setting posts is
not sinking them deep enough. If
you don't go below the frost line,
seasonal movement of the soil due to
the freezelthaw cycle can literally
push your posts out ofthe ground.
By going below the frost line,
you ensure that frost won't form
under the end of the post where it
can push the post upward.Typically,
you slrould go down at least 24",but
check with the local building
inspector to find out the proper
depth in your area. Going deeper
also provides greater lateral support
so your posts won't lean under pres-
sure from the wind or other forces.
A clamshell digger (near left) or a
post auger (far left) is standard equip-
ment for digging post holes by hand
(FIG. 1). If you have a great number
of holes to dig or the soil has a high
clay content. consider renting a
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power auger.The post hole diameter
should be roughly three times the
post thickness (72" for a 4x4) so the
concrete footing around the post will
be thick enough to provide the
required strength.
When you reach the proper
depth, flare the walls of the hole,
starting about 12" above the bottom
to create a bell shape. This provides
additional resistance to the uoward
forces of the frost.
REST THE FOST IN A GRAVET BED
The second most common mistake
beginners make is to encase the
entire bottom end of the post in
concrete. As any post dries and
shrinks, it will pull away from the
concrete, allowing water running
down the post to collect in this concrete
"cup." This in turn can cause
the post to rot prematurely. (lt's
advisable to use pressure-treated
lumber anytime the wood is in
direct contact with the ground.)
Instead, set the post on top of
several inches of gravel to allow
water to drain away (rIG.2).