Horse Fencing - Installing the Posts

While horses need plenty of land to exercise and grass to graze on, they also must be fenced in.  Remember, good fencing makes good neighbors.  

Fencing for horses can be a back breaking job.  The ease of digging the holes depends on:

• Type of soil,

• Soil moisture present,

• Thickness of existing sod, and

• Type of tools you have available.
  

In this article we discuss how to get the holes dug.  We cover how to:

• Hand dig,

• Machine dig, and

• Drive the posts.

Other articles discuss the types of fencing, installing wire fencing and board fencing.

Post hole auger

Marking for the Holes

Before you get started, see about cutting the grass or bush hogging the area.  This will make it easier to see the marker flags and reduce the amount of grass which will tangle up the auger.  For most board fencing the spacing between centers should be 8 feet.  We suggest that you shorten this to 7' 9".  This will allow for the occasional split on the board end and ensure that that the boards cover the span.  Furthermore, by clearing the grass, this will make it much easier to gather the loose dirt and repack the hole. To ensure a straight line or gentle curve, stretch out a light rope or masons line.  You may need to adjust the flag positions a few times.

Here, we are showing a bundle of 3/4 posts.  Post lengths are 7 or 8 feet. For wire fencing round or 3/4 posts are typically used.  For oak board fencing (1" x 6"), a half-round posts is typically used.  These fence posts are pressure treated. Locust posts will last longer, but are often more difficult to locate.

Drag and distribute the posts, one near each planned hole.  It's handy to have an old pick-up truck for this job. Be sure to wear heavy leather gloves as the splinters from treated wood can cause infections easily.

Bundle of posts

Set flags every 8 feet

Lay out the post near each planned hole

Hand Digging the Holes

If you do not have a tractor or a friendly local farmer, you'll need to roll up your sleeves and start digging by hand.  This may seem like a tremendous amount of work, but with practice and good soil conditions you can complete several holes an hour.

Post hole digging by hand takes both strength and stamina.  It helps if you start by removing the sod using an ordinary shovel.  Set the divit aside and use this to complete the hole after the post is set.

If the ground is dry, fill the hole with water and move on the next hole. Return to this hole after the water has percolated in.

To help loosen the soil, use a digging iron.  We recommend one with a small blade end.  This will allow you to shape and scrape the inside of the hole as you dig. Try to keep the hole to 6 to 9 inches in diameter and as vertical as possible.

Continue digging until you have reached as far as you can.  This should be at least 26", though 30" or more is preferable.  The more time you spend now, the more plumb your fence will be after a few years.  Between the horses leaning and the wind blowing, strive for the deepest hole you can. 

Using a clam shell or post hole digger

Using a digging iron to loosen the soil

Reach as deep as you can with the clam shell

Using a Tractor and Auger

A tractor outfitted with a 3-point hitch will accommodate an auger.  The typical tractor should be at least 25 HP.  The auger attaches to the tractor and normally the weight is sufficient to dig the hole.  A hydraulic power unit is available to add a downward force, but is not usually needed in most situations.

Augers are available is several diameters.  For fence post, we recommend a 12" auger, especially when working on slopping or somewhat rocky soil conditions.  The 9" auger is large enough for the post, but the extra room of the 12" auger allows for repositioning of the post in the hole.  Also on hillside, it is difficult to get the hole dug straight down. 

When selecting an auger, choose a good quality one with replaceable cutter blades.  These will wear done with several dozen holes.  Dull blades simply won't cut in.

Tractor and auger

Auger

Replaceable auger cutter blades

Backfilling the Hole

For most horse fencing, backfilling the hole with dirt is usually adequate.  For very sandy soil conditions, you may need to to backfill with concrete.  In the clay rich soil for our project, the soil when properly compacted becomes very hard and dense.  

The key to success of a good fence job is in setting the posts.  Be sure to run a string or masons line between the posts, both along the top and along the base.  Adjust the position of the post in the hole to be sure that your post are in proper alignment.   The posts should to be vertically plumb in all directions.

Your digging iron may have a rounded end, but we recommend that you make your own tamper.  We use a 6-foot piece of 1-1/2" closet pole and attach a 6" to 8" section of threaded pipe and end cap.  A bolt is added to keep it attached.  This "home-made" tamper will be heavy enough for back filling and won't wear you out near as quickly as using a heavy digging iron. 

Back fill the hole in lifts of 4" to 6" at a time.  Tamp between each lift.  Continue until the entire hole is completely backfilled.  If you can find the original divit, replace this.

Tamper for backfilling the hole

Tamp the backfill in layers

Tamp until hole is filled

Driving the Posts

You can also drive posts directly without digging any hole.  Outfitted to a tractor or truck, a post driver can get the job done more quickly, if the soil conditions are right.  

The driver uses a hydraulic system to lift a weight and "drive" or pound the post into the ground without any digging.  Occasionally a rock or tree root gets in the way and holes must be hand dug. 

Special Considerations

Pay attention to where your fence crosses underground utilities.  In our job, we were crossing an underground fiber cable and had the company mark the location.  We carefully hand dug a square, inching our way by hand. Here we found the tape marking the cable was buried about a foot beneath the tape.

Truck mounted rig for driving posts

Driving posts

Special care for underground utilities