Selecting Wire Fencing Materials

Selecting Wire Fencing Materials

Written by Joseph M. Zulovich

Revised by Steellong Company

The purpose of this publication is to assist you in selecting materials for your fence.

Fence posts

Posts used to support fencing are available in either wood or steel in a variety of sizes and shapes. Selection of a post type for your fence should be based on:

·        Availability and cost of the post

·        How long you expect the finished fence to last.

Wooden posts are generally less expensive than steel posts. For permanent fencing, you should select either a decay-resistant variety such as Osage orange or posts that have been pressure-treated with a preservative material.
Wood preservatives help guard against decay. Several types of preservatives are available, but the most commonly used for posts are pentachlorophenol (penta) and creosote. Pressure treatment is a commercial process that forces preservative into the wood under pressure. A preservative retention of six to nine pounds per cubic foot of wood is desirable for fence post treatment. Surface application of preservative to wooden posts is not recommended because wood will not absorb enough preservative to give effective protection from decay.
 

Wooden posts are available in lengths from 5-1/2 to 8 feet and in top diameters of 2-1/2 to 8 inches or larger. The larger the top diameter, the stronger the post. A 4-inch post has twice the strength of a 3-inch post and a 5-inch post has four times the strength of a 3-inch post. Line posts can be as small as 2-1/2 inches, but a minimum of 3-1/2 inches will provide a stronger, more durable fence. Corner posts and gate posts should have a minimum top diameter of 8 inches. Posts used to brace corner posts or to provide added strength in lines of steel posts should have at least a 5-inch top diameter.

Post length will be determined by the combination of fence height and depth of setting. Anchor posts should be set a minimum of 3-1/2 feet into the ground. Line posts are set 2 to 2-1/2 feet into the ground. Add together the depth of setting, the height of the top wire above ground, and an additional 6 inches to obtain required post length. For example, a corner post set 3-1/2 feet deep for a 4-foot-high fence would have to be 8 feet long.

Wooden post sizes are usually given in inches top diameter, then length in feet. A 7-inch top diameter post, 8-feet long would be referred to as a 7" by 8' or 7" x 8'.

Steel posts offer a number of advantages over wooden posts. They are lighter in weight, fireproof, extremely durable, and relatively easy to drive. They also ground fence against lightning when in contact with moist soil.

The common types of steel posts available include "U" Bar, Studded "Y," Punched channel and Studded "T." Steel posts are available in lengths varying from 5 to 8 feet in 6-inch increments. Steel posts normally cost more than wooden posts and can be bent or forced out of line by livestock crowding. Wooden anchor posts placed every 50 to 75 feet are sometimes used to provide added bending resistance for steel line posts.

Wire and protective coatings

Many different types of wire are available for fencing. The two most common for pasture use are barbed wire and woven wire. A satisfactory fence may be constructed of either type or a combination of both types.

Most wire sold today has a coating to protect the wire from rust and corrosion. Galvanizing is the most common protective coating. The degree of protection depends on thickness of galvanizing and is classified into three categories; Classes I, II, and III. Class I has the thinnest coating and the shortest life expectancy. Nine-gage wire with Class I coating will start showing general rusting in 8 to 10 years, while the same wire with Class III coating will show rust in 15 to 20 years.

Aluminum coating is also being used to protect some wire manufactured today. Under the same climatic conditions, aluminum-coated fencing will resist corrosion three to five times longer than galvanized wire with the same thickness of coating.

The stay or vertical wires in woven wire are 6 or 12 inches apart and usually the same gage as the intermediate wire.

The style or design of a woven wire is designated by a three- or four-digit number. The last two digits indicate the height of the wire in inches, while the first one or two digits indicate the number of line wires in the fence. In some cases, style numbers may carry additional digits that indicate, respectively, the spacing of vertical stays and the gage size of intermediate wire. For example, a style 1047-6-9 is a 47-inch-high fence with 10 line wires, vertical stays every 6 inches and 9 gage intermediate wire.

Table 2

   Weight classification and wire size for woven wire stock fencing

Barbed wire

Barbed wire is less expensive and somewhat easier to work with than woven wire fencing. It is sold in 80-rod rolls (1,320 feet = 1/4 mile) and is available in several wire sizes and patterns. The more common sizes are listed in Table 3.

Table 3

   Available sizes and description for barbed wire

Smooth wire

Nine-gage smooth wire with galvanized coating is used in brace assemblies. This wire is usually sold by the pound and is normally available in 10-pound coils.

Fasteners

Steel post manufacturers provide specially designed metal clips to fasten wire to the posts. Make sure your dealer provides you with a supply of these when you buy steel posts.

Wire is normally fastened to wooden posts with 1-1/2 to 2-inch staples. Staples are sold by the pound.

Fence styles