Installing a Guide Wire for High Tensile Fencing

One of the key steps in successfully constructing a good looking farm fence (or any fence – for that matter) is installing a guide wire to use for putting in line posts. Without a guide wire (or one that is installed too quickly) your fence posts will not be in a straight line.

I feel sure that we would all like to build fences that are true and straight. One, where you can sight down the fence line when you are done and everything lines up to your satisfaction. But, I would also feel sure that most of us have at one time or another NOT spent enough time on the guide wire.

Straight High Tensile Fence

Here's a shot of a really straight fence line (click to enlarge) using PasturePro Posts.

The guide wire will also help in lining up your brace posts and gateways. Technically, the guide wire should be stretched immediately after the corner or end posts are secure and before any other posts or bracing are installed.

With high tensile fencing, you can use the bottom strand of your fence as your guide wire. Simply install your end insulators and attach the guide wire. Install a wire strainer or tensioner at about the midway point and tighten it up good and snug, so that you can snap it up and down like a chalk line.

If you are going over hills and thru dips, then you will need to physically walk out to all the high spots and assure that the guide wire is in a straight line without any obstructions, horizontally. [Note: a 6” to 12” variance, out of true line, is not very distinguishable to the naked eye, but after the wire is tensioned up it will be trying to bend the line post towards the true line.]

In the photo above, extra care was taken with the guide wire to make sure that the fence line was straight, even through the dips and ridges of this pasture. Though the fence line itself is straight, you can see the downward pressure on the posts from the dip has caused the posts to lean. Using a boss post at the crest of the hill as well as the bottom of the dip is recommended to prevent this from happening.

After your guide wire is installed, straightened and established, you can now install your brace posts, gate posts and any line bosses that you want to incorporate into your fence line. I do recommend using line bosses periodically and especially at ridge tops or rises. They just add a little extra stiffness to the fence where you need it.


Now you can go ahead and attach the guide wire to the brace, gate and boss posts. After this is done, you are now ready to begin installing your actual line posts.


About Gary Duncan

Gary has been active in the fence business for over 15 years. He also raises Highland cattle in a management intensive grazing system and was the first person to market the PasturePro post back in 2005. He enjoys discussing all things grazing and is the main contributor to the blog.
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13 Responses to Installing a Guide Wire for High Tensile Fencing

  1. avatar Ryan says:

    Another challenge to getting a straight fence is augering the holes. I can be very hard to get the auger placed just perfectly. Then sure enough about 6 inches down it will hit a rock and start to angle. Speaking of angles, making sure the auger is perfectly vertical is another challenge. I am thinking about trying a post pounder this year. Perhaps it will be easier to keep the posts straight. Another word to the wise, have another person present to hold the guide wire away from the auger. If it catches that wire life gets interesting real quick.

    • avatar Gary Duncan says:

      ALL good points Ryan! I see more hydraulic post drivers being used every year, on farms, and would bet that once you try one you will be hooked. As you probably already know, the better ones also have rock spikes which would make them great for the rocks that you encounter.
      Thanks for your comments.

      • avatar Gary Duncan says:

        PS: regarding the guide wire when augering…..I usually have some tread in plastic posts with me and use them to hold the guide wire away from the hole, after I mark it. Fortunately, I’ve not caught a wire up in an auger, but have come really close, several times :-)

  2. avatar Steve says:

    I’ve had the same experience with keeping the auger hole in line and unfortunately I think you will find the same concerns with a post pounder when you hit rock. They start straight, but still take time keeping them straight in rocky ground. Rocks or hills make building a straight fence a challenge and we have both..

    Besides snapping the guide wire to ensure straightness of the guide wire we often use two portable posts and step them in along the guide wire 100-200 feet apart and then site the two posts back to the corner posts to make sure the wire is straight and hasn’t hung up on grass or rocks etc. and is out of line. It’s the old three point theory of geometry ensuring a straight line.

  3. avatar Lydia Ernszt says:

    We used a lazer sight to get our fence posts straight… works great! Usually on short stretches we will site the braces and end posts then string our lowest wire and use it as a guide… using the “Grasshopper” for the hole makes it easy and all you have to do is put your foot down on the wire to hold it so the head of the “Grasshopper” does not hit the wire as you are driving it into the ground.

    • avatar Gary Duncan says:

      Hi Lydia, a laser sight sounds like a great way to sight in a straight fenceline. I’ve always wanted to try one.
      And yes, the pilot driver really does help you get all your line posts straight, in line and consistent. I sometimes use one even when I technically don’t really need it for rocks or hard ground. If you pilot a straight hole, then your post will for sure be straight.

  4. avatar Ben says:

    Has anyone ever tried putting the brace post centered on the guide wire, drilling the post then threading the wire through with a piece of insulated tubing? I’ve been thinking of giving it a try, should make the brace a little stronger I think.

    • avatar Gary Duncan says:

      Hi Ben, I, like yourself, have thought of this idea. But, have never actually installed it this way either. Makes sense to me and would be very clean. Treated posts would drill nicely, however with some of our midwest seasoned “Hedge” you would probably wear out some bits drilling it. Another downside, might be the fact that your fence wire would be touching or very close to your brace tensioning wire. Send us some pictures after you do one !

  5. avatar Tom Gentry says:

    Hi Gary,
    I’ve enjoyed reading your informative tips. I recently purchased a Shaffer 10″ hydraulic post driver. I am driving 5″-6″ x 8′ post in gently sloping ground. Like you, I LOVE straight fence lines. However I am having an extremely difficult time achieving a straight line. I pull a guide line so the post bottoms are in line but the angle of the drive inevitably varies giving the appearance of a crooked fence. I place a 4′ level on the driver each time and try to watch for movement or play as I drive the post. To no avail…crooked post! Any tips? I have about 5000′ to build and sure don’t want to look out my window at crooked fence for the next 20 years. By the way, the soil is good semi firm clay and there are very few rocks. Thanks!

    • avatar Gary Duncan says:

      Hi Tom,
      Thank you for your comments.
      I feel for your agony and can associate with you looking out the window every day at your fence. I built a wrap around porch a few years back and had a little problem with a rafter on the hip. Every time I sit in the porch swing it haunts me and someday I’m going to rip that roof off and redo it.
      Anyway, about the post driving. I have not personally logged a lot of time on a hydraulic post driver but know that when it comes any tool, you get better with practice! In fact, I just called a friend that sells a ton of post drivers and his advice was: to go to the back 40 and practice driving posts. You will get a better “feel” for it. I well remember the first day I spent on a skid steer with all hand toggles. There was a few hours involved in the learning curve of that one.
      While levels are neccesary (on the post as well as the driver), it also helps me to position things so that I can also get a good “eyeball” as I sight down the fence as I progress. Depending on the lay of the land I also sometimes install some intermediate line posts just to use as an eyeball guide when going over and down rises and dips. Sometimes a few steps back can give a better perspective as well.
      Also, in some cases (where straightness is ultra important) I have installed some line bosses, then went ahead and pulled a second guide wire at around a three foot height (you need the line bosses to hold the wire up off the ground). This will give you a little more visual perspective, relating to the in/out line. But then you have to work around it and keep it safely out of danger with the driver.
      Hope some of this helps. I would also suggest that you call Kencove Farm Fence at 800.536.2683 and visit with their post driver specialists, either Billy Erwin or Hoss. They can likely give you some tips and pointers that could save you some frustrations.
      Keep in touch and let us know how it progresses for you.
      PS: are you using sharpened posts or blunt end ? I’ve been told that sharpened posts tend to turn more as you drive them.

  6. avatar Steve says:

    Hi Gary,

    We used to drive a lot of wood and pipe posts with an old Danuser PTO driver and had similar experiences as Tom in driving all the posts straight. Often the posts looked like an English smile, posts pointing in every direction. One thing we found helpful on ground with similar slope was driving so the tires of the tractor straddled the guide wire rather than backing up to every post. This helped to keep the angle of the driver the same. Fewer adjustments needed. We also made pilot holes with a bar, for our ground is rocky and it helped to have the rocks pushed out of the way so the posts could be driven with less interference from rocks.

    But in the end, we almost always had to gently, very gently, push the posts to plumb with the front end loader on the tractor. One person would stand behind the corner post and site the posts, signaling to the tractor operator to push and pull the post to plumb. If we loosened the posts doing this we would take our tamper and tamp and firm up the posts after we had attached the wires.

    I hope someone has a better way to install straight posts. The new posts drivers look to be a lot easier to adjust the angle of the sleeve than our old Danuser and I’m sure that has to make the job easier.

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