Fencing Management: Posts, Insulators and Gates

Table of Contents

1. Posts
2. Brace Posts
3. Insulators
4. Gates
5. Other Fencing Management Recommendations
   • Electrical Fencing
   • Energizers
   • Regulations, Predators, and Maintenance
   • Protection From Lightning
6. Related Links

Posts

Choice includes cedar, insultimber, plastic, steel stakes, fibreglass and trees. Steel stakes will ground the fence if an insulator is cracked. With trees, leave the nails loose to prevent the tree growing around the insulator. This can result in plastic and nails lodged in trees. The type of post you use depends on whether the fence is permanent or temporary, the type and number of wires, the distance between posts, and the cost.

A permanent fence with 2 or more high tensile wires requires strong braces. This is the last line of defence. However posts are needed just to hold up the wires.

A temporary fence should be easy to set up and take down. Plastic, steel or fibreglass posts are flexible. Tumblewheel systems are convenient, but more expensive.

The distance between posts will vary with the lay of the land. Posts can be placed 100 ft or more apart on level land. The further distance apart the stronger the post needed to carry the weight. A cedar post with a 5 in. or 6  in. top or insultimber is satisfactory. Spacers are placed between posts to keep wires equal distance apart. On rolling land, posts are closer to enable the fence to follow the hills and valleys. Place posts at right angles to the ground surface on slopes where possible to maintain the fence height.

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Brace Posts

With a high tensile, smooth wire fence, the wire load is directly on the brace posts. The wires are suspended on posts by the insulators and move freely. This means the brace posts must take the brunt of any force on the wire and the weight of the wires. Keep in mind stronger braces are required where a suspension effect is desired.

Tests done by Alberta Agriculture show that 2 brace designs proved the strongest of those tested. They are the 10-ft diagonal end brace and the 10-ft single span horizontal end brace.

Figure 5-3. 10-ft diagonal end brace and 10-ft single span horizontal end brace.

The double span end brace was given a lower rating because of the extra difficulty and expense of construction. Also all 3 posts must be directly in line to be effective.

Soil type has a bearing on the effectiveness of an end brace. Friction between the soil and the post is the key. Heavy clay provides a lot of friction while sandy soil has less. Larger end posts are advisable in sandy soil.

Insulators

Except for self-insulating posts like plastic, insultimber or fibreglass, insulators are necessary. Insulators hold the wire to the post and prevent it from shorting out.

Insulators are usually porcelain or plastic. Porcelain will last longer but breaks more easily. Nylon, polyethylene and fibreglass are also available. Insulators with protection from ultraviolet rays will last longer.

Wire should move freely through the post insulator. This allows the entire fence to absorb the force of a fallen tree or charging animal.

Gates

Gates may consist of a wire spring or polytape with a handle. The gate must be visible and control livestock, particularly on a perimeter fence. A hot wire is often run through insulated cable underneath the gate opening . This leaves the fence charged if the gate is open.

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Related Links

... on forages and pastures, visit Forages and Pastures (OMAF)
... on weed control, order Publication 75 Guide to Weed Control: Forage Crops
... on agronomy for field crops, order Pub. 811 Agronomy Guide for Field Crops: Chapter 5 Forages
... on field crop protection, order Publication 812, Field Crop Protection Guide
... on livestock, visit Livestock (OMAF)

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