-
Table 1: Life Expectancy of Untreated and Treated
Fence Posts (Years)
Kind of Wood
Hot
Un Pressure and Cold
treated Treated Cold Soak
Bath
Western Red
Cedar
12-15 20-25 20-25 -
Lodgepole &
Ponderosa
Pine
2-4 20-25 15-20 10-20
Aspen or
Cottonwood
1-3 15-20 10-15 5-10
Douglas Fir
& Western
Hemlock
3-6 20-35 15-25 10-20
382A OR-Specification
Natural Resources Conservation Service, Oregon
February 2015
FENCE (standard wire) SPECIFICATION SHEET
MATERIALS
Wood Posts: Line posts shall have a minimum top
diameter of 3 inches and shall be a minimum of 6 feet
in length.
Corner, gate and brace posts shall have a
minimum top diameter of 5 inches and shall be a
minimum of 7 feet in length. Braces shall have a
minimum top diameter of 4 inches and shall be a
minimum of 6 feet in length.
Steel Posts:
Steel
line posts shall be the “T”, “U” or
“Y” type with a welded or riveted anchor plate near
the bottom (minimum 18 inches square area) and
have suitable corrugations,
knobs, studs or grooves
for fastening the wire. Line posts shall
weigh at least
1.33 pounds per linear foot
of length and shall be a
minimum of 5.5 feet long.
Steel Pipe Posts: Steel pipe corner, gate or brace
posts shall be a minimum diameter of 2 inches,
Schedule 40 (2.375-inch O.D.) and at
least
7 feet
long.
Bracing shall
be a minimum of 1-1/2 inch
nominal diameter, Schedule 40 Pipe.
Brace fittings
and clamps shall be galvanized.
Angle Section Posts:
Angle section posts shall have
nominal sectional dimensions of 2.5 by 2.5 by
0.25
inches thick and at
least 7 feet
in length.
Braces
shall be of the same size dimensions as corner and
gate posts and shall
be a minimum of 6 feet in length.
Woven Wire: Woven wire materials
shall conform to
ASTM A 116. The top and bottom wires shall be
zinc-coated, 11-gauge or heavier and the line and
stay wires shall be zinc-coated 14.5-gauge or
heavier.
Barbed Wire: Barbed wire shall be composed of two
strands of 12.5-gauge zinc coated wire wrapped
around each other, with 2-point 14 gauge barbs
spaced no more than 5 inches apart conforming to
ASTM A 121.
Smooth Wire: Smooth wire shall be a single steel
wire of 9-gauge or heavier, two wrapped strands of
12.5-gauge or heavier wire or 12.5-gauge or heavier
hi-tensile wire. Wire shall have a minimum tensile
strength of 45,000 psi.
Wire Panel Fasteners: Staples shall be 9-gauge or
heavier and have a minimum length of 1.5 inches,
except 1.0 inch staples are allowed on very hard
woods. Fasteners for use with steel posts shall be
12-gauge or heavier zinc coated wir
e.
S
tays: Wire stays shall be 9.5-gauge or heavier, zinc
coated, twisted wire. The length shall be at least two
inches longer than the distance between the top and
the bottom strands of the fence. Wood stays shall be
sound, straight pieces at least 2 inches in diameter.
INSTALLATION
The fence shall be reasonably straight and shall not
deviate more than 12 inches between any corner and
gate or line brace assembly.
Post Depth: Line steel posts shall be set a minimum
depth of 1.5 feet and wood line posts shall be set to a
minimum depth of 2 feet, unless otherwise specified.
Gate, corner and brace posts shall be set to a
minimum depth of 3 feet, unless otherwise specified.
Steel pipe and angle section posts shall be
embedded in a 12-inch circular or square concrete
pier, except when set in firm rock.
Post Spacing: The maximum post spacing interval
shall be 20 feet on fences without fence stays, 25
feet with one stay between posts and 30 feet with two
stays between posts.
Line Bracing: Line brace assemblies shall be
located at all corners, gates and abrupt changes in
vertical topography (generally considered as 15
degrees). On straight reaches of fencing line braces
shall be installed at a spacing of no more than 1300
feet.
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