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Lay Out and Dig a Post Hole

Find tips and instructions for laying out and digging post holes for your new fence.

Instructions

Laying out a fence means lining up and marking the location of the posts before actually installing them.

Caution

Before beginning any excavation, check for underground utilities. Call the North America One Call Referral Service at 1-888-258-0808 (or just dial 811) for a national directory of utility companies.

Laying Out the Fence

Step 1

Placing Batterboards.

Begin by making some batterboards (two stakes and a horizontal cross piece) out of furring strips and screws. Placed at the corners of your layout, batterboards support the layout strings and allow you to easily make adjustments by simply moving the strings.

Step 2

Start the fence layout at the corner of the house, outbuilding or other hardscape feature.

Step 3

Drive a batterboard into the ground to mark where the fence will start. Tie mason’s string to the batterboard to mark the line where the edges of the posts will be set.

  • If you plan to install your panels between the posts, set the strings to the outside post edge.
  • If you plan to install pickets or panels to the outside of the posts, set the strings to the inside post edge.
  • Be sure to keep in mind that if you’re attaching to the face of the post, you need to account for the rails and pickets when lining up the fence with the edge of the house.

Step 4

Measure for each run of your fence. Use batterboards and stretch mason’s string between them to mark the layout. Use two batterboards at corners.

Step 5

Review the fence layout and adjust as needed to use full panels or to have no fence sections less than 2 feet wide. Partial sections should be located at corners or near gates.

Step 6

Verify that the fence layout is square.

  1. From an outside corner, measure 3 feet along one line, and make a mark on the string.
  2. Measure 4 feet along the other line, and make a mark on the string.
  3. Measure the diagonal distance between the two marks and adjust the stakes as needed so the distance is 5 feet.
  4. Repeat the squaring process at all fence corners.

Step 7

Drive stakes at the locations where fence posts will be installed. Make sure the stakes are positioned against the string. The distance between posts is dictated by the size of prebuilt panels, horizontal rails or local building regulations. Typically, spacing is between 5 feet and 8 feet.

  • For prebuilt panel kits, the manufacturer will recommend post spacing, depending on whether the panels fit on the face or between the posts. If they attach between the posts, typically it’s the width of the panels, plus the thickness of the brackets, plus the half the width of the posts. For best results with prebuilt panels, only mark three to four holes at a time.
  • If you’re attaching prebuilt panels to the face of the posts, the post spacing will be the width of the panels.
  • If you’re installing a component-built fence, typically the spacing will be determined by the length of the rails to which you’ll attach the pickets, unless otherwise noted by local building regulations. For instance, if you’re using 16-foot rails, they can span three posts, so your spacing will be 8 feet. You can dig all the holes at the same time for a component-built fence

If the yard isn’t level, start post measurements at the highest points and work downhill.

  • For a panel-built fence, measure horizontally rather than along the slope. Use a line level if necessary.
  • For a component-built fence — pickets that will be attached individually — measure along the slope, since the rails will follow the contour of the land.

Step 8

Insert stakes at the planned location for gates, including hardware in the width.

Digging Post Holes

Step 1

Marking the Post Hole Center.

Mark the center for the first post on the ground. It should be set back half the width of the post from the string.

Good to Know

After marking your hole, mark where the layout string is tied to the batterboards, and remove the strings to make digging easier.

Step 2

Dig the first post hole. Local building code will dictate post hole depth and diameter. Typically, the diameter is triple the width of the post (12 inches for a 4-inch-by-4-inch post). The hole depth should be below the frost line. Typically, this means to a depth of 30 inches (24 inches for post, 4 inches for gravel and 2 inches below ground level).

Step 3

Dig the second and third post holes.

  • For panel fences, don't dig additional post holes until the first three posts and panels are installed. This allows you to make adjustments as needed for spacing posts and panels.
  • For component fences, you may continue digging post holes as long as you're sure that the distance between the posts will be at or less than the length of the horizontal rails.
Good to Know

Digging post holes is easiest with a power earth auger. A shovel or spade may take longer, but they’re good for cutting overgrown roots in a hole. A spud bar works well for loosening dirt from the sides. Clam-shell post hole diggers can help remove loose dirt in the bottom of the hole.