Learn how to install an electric fence by learning about conductors, corner posts, and insulators before buying quality electric fencing materials and spending time on construction.
As a containment system for livestock, a well-made electric fence can be both highly effective and relatively low maintenance. I’m not opposed to other methods of fencing, such as barbed wire; I’m just opposed to paying for them. If you already have a barbed wire fence, good. If you don’t have fence and need to build one, the most economical way — by a wide margin — is to build an electric fence the right way.
Unfortunately, the first permanent electric fence I built was neither effective nor low maintenance, because it wasn’t well-built. I struggled with escaped livestock, the constant need for repairs, and ceaseless calls from angry neighbors. (I’m lucky to have good neighbors, since cattle walking through their cornfield will test the patience of even the best of friends.)
I’ve made just about every possible construction mistake when building electric fences. Had I spent a little more time on construction, a little more money on the right materials, and a lot more time listening to advice from people with more experience, I would’ve saved a ton of time, money, and grief. Foremost among those mistakes: I used metal line posts and 14-gauge wire; I attached wires directly to live trees; I alternated hot wires and ground wires; and I alternated barbed wire with smooth. Learn from my mistakes as I explain why all those were poor choices, and then adopt the more effective methods I’ve learned along the way.
Conductors
The wire or cable conducts the electricity and is thus called a “conductor,” which is a good place to start.
For my first fence, I used 14-gauge wire and barbed wire. Both are bad choices for an electric fence. That size of wire is simply too weak for permanent use, and it kinks and breaks easily. Once it begins to break, it’ll break over and over again. I suspect my fence broke every time a deer hit it, a cow brushed against it, or the wind blew.
Barbed wire, on the other hand, is quite strong, but the barbs in combination with electricity make it hazardous, since it can trap and kill livestock and pets. Because skin is an effective insulator, a barb can penetrate an animal’s skin and then send an extremely high voltage, which can be dangerous for the animal. In my fence, the smooth wire was constantly getting wrapped around the barbed wire, and since the smooth wire was hot and the barbed wire was grounded, the fence was constantly shorting out.
Instead of this failed setup, here are some conductor materials I recommend:
12.5-gauge high-tensile wire. Far stronger than 14-gauge soft wire, this material isn’t prone to kinking. It’s stiff and hard to work with and must be rolled out with a device called a “spinning jenny.” It’s hard to take up and reuse.
16-gauge aircraft cable. This material is flexible and easy to work with, though not as strong as 12.5-gauge high-tensile wire. It’s not commonly available, but, if you have a source, it makes for a great fencing material. Because it’s flexible and easy to put up and take down, it’s a favorite material of mine for temporary fencing and interior subdivisions.
Barbless twisted two-strand wire. This is essentially barbed wire without the barbs. It’s for situations where something stronger than 12.5-gauge is called for, such as when you know animals will push on the wire.
Corner Posts
One reason electric fences are cheaper is because they don’t require elaborate bracing the way barbed wire fences do. A single well-anchored corner post is all you’ll need. There are many options for corner posts, but my favorites are natural wood, in particular Osage orange, which is resistant to decay and can last for up to 50 years in the ground. No other post comes close. But Osage orange wood hardens over time and becomes difficult to drive staples into, and it’s heavy and otherwise hard to work with. In areas where Osage orange doesn’t grow, options include catalpa, bald cypress, redwood, red cedar, mulberry, and black locust; these can last 20 years or more. In areas without native decay-resistant trees, creosote-treated pine posts are the best option.
To anchor corner posts, tamp loose gravel (rather than soil) around the base of the post to provide free drainage and greatly reduce the rate of post decay in the ground. Putting concrete around a fence post can strengthen its anchoring ability, but it should only be poured in the bottom of the hole, with gravel around it. If the hole is filled with concrete, water will move around and under the concrete, and, if it freezes, will force the concrete plug out of the ground. Also, over time, as the post dries and shrinks, a gap will form between it and the concrete that’s level with the soil surface. This will trap water and cause the post to rot faster.
Line posts are used to hold up the conductors and maintain spacing between them. I used steel T-posts in my initial fence. As it turns out, any metal post is a bad choice. The main cause of electric fence problems is grounding out, and the easiest way to cause a fence to ground out is for a piece of metal anchored in the ground to accidentally touch the wire.
Every single metal post is a potential fence fault. Never use metal posts in an electric fence system, as it’s asking for trouble. Avoid the rebar step-in posts as well, and the plastic claw insulators so commonly used in temporary electric fencing. Once a deer hits the wire and pops the fingers off the insulator, the wire will snap back against the post and ground out.
Instead, posts should be self-insulated. Wood-plastic composite posts are probably the best line posts. Not only are they flexible, lightweight, and resistant to rot, but they don’t splinter, are easy to drive into the ground, and don’t conduct electricity. PVC T-posts are another good choice. They’re also free of splinters, nonconductive, and easy to drive. Plus, they have the added advantage of being fire-resistant.
A tier below both of those options is a fiberglass rod. You can buy used fiberglass sucker rods cheaply as oil field surplus. Fiberglass rods also come in plastic-coated, relatively splinter-free versions, in diameters ranging from 3/8 inch up to 1 inch. These are more user-friendly than the used sucker rod, but they’re also more expensive. Plastic-coated fiberglass rods are quite sturdy in larger diameters, and they’re nonconductive, but they’re heavy, hard to drive into the ground, quick to splinter, and hazardous to handle without gloves. An additional drawback of these rods is that they’re pale green and hard to spot in green grass. I use plastic-coated fiberglass rods because they’re cheap, but as soon as I get them, I spray-paint them blaze orange. This glues any splinters to the rod, making it safer to handle. The orange paint, coupled with a single wrap of aluminum foil tape, vastly improves visibility. Otherwise, my pickup tends to find them before I do. The best way to attach wire to these posts is to wrap a wire loop around the fence wire and run it through the post.
Commercial fiberglass fence posts are also available. These are coated with a plastic that’s resistant to ultraviolet (UV) light and that reduces splintering. These posts come in diameters ranging from 3/8 inch up to 1 inch. I use the 1/2-inch-diameter fiberglass rods for temporary fencing, such as in cornfields, and for interior subdivision fences.
There are three options for holding wire to small-diameter fiberglass posts. My favorite is a wire loop that acts like a spring to hold the wire to the post. A simple twist of the post can be used to attach or detach the wire. The second is a flat metal plate with two rough-edged holes in it, bent in a V-shape, with the post inserted through it. This is the strongest option, but it’s difficult to remove the wire once attached. It’s the best choice for permanent fences. Finally, you could use a claw-type insulator. These are commonly used on rebar posts, but they make a relatively weak attachment and are prone to breakage.
Component Parts
Insulators. Though not necessary for line posts, insulators are necessary for attachment at corners and end posts. I like two main types of insulators for ends and corners: the double-U and the bullnose. Black plastic insulators are preferable, since black plastic tends to be more resistant to degradation by UV rays. Porcelain is less desirable, as it tends to develop small cracks over time that can hold water and conduct electricity. Gray porcelain is stronger than white.
Gripples. A fantastic little invention, the Gripple is a device with two small holes in it, into which two wires are inserted from opposite directions. The wires can go into the holes, but once they’re in, camlocks prevent them from being pulled out. Gripples can be used as both splicers and tensioners.
Gates. Thesecome in all forms. Besides the usual tubular metal swinging gates, there are also electric bungee cords, electrified springs, and all sorts of other devices. For most of my internal gates, I use a stretch of electric rope attached to an Old Ironsides gate handle. It’s durable, flexible, and highly visible.
Chargers. I can offer one solid piece of advice about chargers: Go big! Size does matter. I want a charger that will make an animal believe Thor smote it with a lightning bolt. This will make it clear to that animal that it should never get close to the fence again. The size of a charger is measured in joules. I use a relatively large (24-joule) charger whenever I can.
Fault finders. A must-have piece of equipment for me, a fault finder not only tests voltage but also reveals any faults in the fence. Look for a combination fault finder and fence charger in which the fault finder can remotely turn the fence charger on and off. This means that once a fault is located, you won’t have to go back to the fence charger, turn it off, go back to the fault, repair it, and go back to the charger to turn it on. The charger can be turned on and off remotely at the site of the fault, saving a lot of time.
Grounding. An electric fence delivers a shock by sending electrons through the animal to the ground. These electrons must be replenished in the charger from the grounding system. The rate of electron replenishment depends on how much surface area is contacted by the ground rod system, as well as the electrical conductivity of the soil. The higher the joule rating of the charger, the better the grounding system must be. At a minimum, use a 6-foot ground rod for every 4 joules of fence charger. More ground rods may be needed if the soil is dry.
I prefer to use threaded, galvanized redi-rods for grounding over commercial ground rods. They’re cheaper, and the threads offer additional surface area. You can attach the ground wires by wrapping them around the rod between two nuts and two flat washers, and then threading the nuts toward each other to ensure excellent contact. Another good grounding option is to use discarded road grader blades, polished with a wire brush and shoved into the soil with a front-end loader.
You should space ground rods 10 feet apart to attain maximum soil volume for extracting electrons around each ground rod. The lead-out wire to the ground rods should be at least the same diameter as the lead-out wire to the fence, or it’ll restrict electron flow. Use a cable rather than a solid wire as a ground lead-out, since cables are more conductive than solid wire for a given diameter.
Dale Strickler finds electric fencing indispensable on his Kansas cattle operation. He’s an agronomist specializing in cover cropping and grazing strategies to build soil health. This is excerpted from his book Managing Pasture (Storey Publishing, 2019).
