MATERIALS & INSTALLATION SPECIFICATIONS A. WIRE All wire will be of new galvanized material and in accordance with criteria outlined in Table 1 which follows ASTM - A 116 (woven wire), and/or ASTM-121 (barbed wire) standards. Galvanization is critical to rust protection of wire and different classes of galvanization provide different levels of protection. Wire with Class I and Class III galvanization meets the minimum level of treatment required to protect the wire from rust for the expected life span. Wires designated as regular, commercial and utility grade does not offer the level of treatment to prevent rust. Most wire manufacturers include wire specifications on fence tags. Table 1. Wire Type Specifications for Barbed, Smooth and Woven Wire Fence WIRE TYPE MINIMUM WIRE SIZE MINIMUM PROTECTIVE COATING STRAND-BREAKING STRENGTHS Standard Double Strand Barbed Wire 12-1/2 gauge with 14 gauge or heavier two-point barbs spaced not more than 5 inches apart. Class I galvanized per ASTM-121 850 pounds or 60,000 psi High-Tensile Double Strand Barbed Wire 15-1/2 gauge four-point barbed Class III galvanized per ASTM-854 1,400 pounds or 135,000 psi Standard Smooth Double Strand Wire 12-1/2 gauge Class I galvanized per ASTM-121 950 pounds or 70,000 psi High-Tensile Single Strand Smooth 12-1/2 gauge Class III galvanized per ASTM-854 1,400 pounds or 135,000 psi Woven Wire, Style 4 – Farm Fence Top and bottom wires, 11 gauge, intermediate and stay wires 14-1/2 gauge Class II zinc coating or equivalent 0.5 oz. per sq. ft. or wire surface. ASTM A-116 standards 950 lbs. minimum 1. Wire Installation Fence wire will be stretched to sufficient tension prior to being fastened to posts. Temperature variations must be considered (wire will tighten in cold weather and expand in hot weather). Wherever possible, wire will be attached to fence post on side receiving most pressure.
Posts need not be new materials, (Railroad Ties and Power Poles are adequate); however, all posts shall meet the minimum criteria for durability and protective coating and be sound and free from decay, with all limbs trimmed substantially flush with the body. Lengths listed below are based on a 42-inch top wire height. Steel pipe needs to be free from corrosion and pitting. BRACE POST TYPE MINIMUM DIAMETER/WEIGHT MINIMUM SETTING DEPTHS MINIMUM LENGTH OTHER Wood-juniper, cedar, osage orange, black locust, redwood, oak or pine (See other) 5 inches 3 feet or 1/3 of post length 7 feet If pine is used it must be pressure treated the entire length of the post. (See Note Below*) BRACE POST TYPE MINIMUM DIAMETER/WEIGHT MINIMUM SETTING DEPTHS MINIMUM LENGTH OTHER Steel, round 2-3/8 inches outside diameter (OD), 3.65 lb./ft. or equivalent 3 feet – set in concrete entire depth. No concrete needed if welded to compression brace. 7 feet Schedule 40 pipe will meet these requirements. Place a metal stay on wires, next to the pipe post so wire cannot be moved vertically. Live trees 6 inches at top wire Wire not wrapped or stapled directly to tree. A wood slat is nailed to the side of the tree and the wires stapled to the slat. *Wood should be treated with EPA approved wood preservative. Rock cribs can be used in rocky areas for corner bracing where soil does not permit post holes to be dug
Table 6. Stay Requirements STAY TYPE MINIMUM DIAMETER/WEIGHT MINIMUM LENGTH Wood - Preferred in high snow areas 1.5 inches diameter Fence wire height + 2 inches Wire – Not to be used in snow areas 9.5 gauge twisted, manufactured for this purpose; galvanized-zinc coated 4 inches + distance between bottom and top wire Fiberglass Especially fabricated for this purpose Fence wire height + 2 inches Table 7. Fence Height and Wire Spacing Requirements INTENDED USE FENCE HEIGHT & WIRE SPACING Domestic livestock control with wildlife consideration. Woven wire is not an alternative for wildlife friendly fencing. 42 inches preferred height – maximum height 48 inches for the top wire. Wire spacing of the top two line wires shall be a minimum of 10 inches apart at the post location. Bottom wire will be a minimum of 14 inches from the ground; 16 inches for antelope (see below for additional considerations for wildlife).