Fence Building Tools: Everything from Posts to Finish

Layout and Marking

Before you dig a single hole, mark the fence line precisely. A string line between corner stakes defines the path. Drive stakes at each corner and gate post location, then run mason's line between them. A line level on the string checks for consistent height if you want the fence to follow a level line rather than the ground contour.

Mark each post location along the string. Standard post spacing is 8 feet on center for most residential fences, which works with standard 8-foot rail lengths. Measure from corner to corner and adjust spacing so you don't end up with an awkward short section at the end. Spray paint or flags mark each post hole location on the ground.

Post Holes and Setting

Post holes need to be about 3 times the width of the post and one-third the length of the post deep, plus 6 inches for gravel at the bottom. For a 6-foot fence with 8-foot posts, that's about 30 inches deep. A two-person post hole digger (clamshell type) works for a few holes. For more than about 10 holes, rent a two-person gas auger. It cuts the work from hours to minutes.

Drop 6 inches of gravel in each hole for drainage, set the post, check plumb with a post level (the kind that straps to the post so your hands are free), and fill with concrete. Fast-setting concrete mix doesn't need water premixed — pour it in dry, add water to the hole, and it sets in about 30 minutes. Brace each post with angled 2x4s staked to the ground until the concrete cures. Check plumb one more time before you walk away.

Rails and Pickets

After the concrete cures (at least 24 hours for standard mix, 4 hours for fast-set), attach the horizontal rails. Two rails for a 4-foot fence, three for a 6-foot fence. A cordless drill or impact driver with structural screws, or a framing nailer with galvanized nails, handles the fastening. Toe-screw or use rail brackets at each post.

Pickets go on the rails with a consistent gap between them. A spacer block cut to the desired gap width speeds this up and keeps everything uniform. An impact driver with exterior-rated screws is faster and more secure than nails. Two screws per rail per picket — one at the top and one at the bottom of each rail. A string line across the top of the pickets keeps the tops even.

Gates

Gates are the trickiest part of a fence because they move and carry their own weight. Build the gate frame from the same lumber as the fence, but add a diagonal brace from the bottom hinge side to the top latch side. This brace prevents the gate from sagging. Without it, every gate eventually droops and drags.

Gate hinges need to be heavy-duty — not the lightweight hinges from the general hardware aisle. Use strap hinges or T-hinges rated for the gate weight. A drill and lag screws attach the hinges to the post. A self-closing spring hinge is worth considering for gates that kids leave open. Gate latches range from simple thumb latches to lockable options. Match the latch style to how the gate will be used.

Finishing

Unfinished wood fences weather to gray within a year or two. If you want to preserve the color, apply a stain or sealant within a few weeks of building. A pump sprayer is the fastest application method for fences. A roller works on flat surfaces but misses the gaps between pickets. Brushes get full coverage but take forever on a long fence.

Back-brush after spraying to work the finish into the wood grain and catch drips. Stain both sides of the fence if possible — moisture enters from both directions, and finishing only one side can cause the boards to cup. Let the stain dry for at least 24 hours before leaning anything against the fence. Plan to reapply every 2 to 3 years for transparent stains, 3 to 5 years for semi-transparent.

Frequently Asked Questions