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How to Build a Fence: Post Holes, Rails, and Pickets Step by Step (2026)

Build a wood privacy fence or picket fence from scratch. This guide covers layout, post hole depth, concrete setting, rail attachment, and picket spacing — for a fence that stays plumb and lasts 20+ years.

Quick Answer

A wood fence starts with post holes at least 1/3 the post length deep (24–30 inches for a 6-foot fence). Set posts in concrete, let cure 24–48 hours, then attach rails and pickets. The critical variables: post depth, concrete quantity, and keeping posts plumb. A fence with posts set too shallow or not plumb will rack and lean within 5 years. Rent a post hole digger — hand-digging 20+ holes will end the project before it starts.

Frequently Asked Questions

How deep should fence post holes be?

Below the frost line — AND at least 1/3 of the total post length. For a 6-foot privacy fence using 8-foot posts: the hole must be at least 24 inches deep, and deeper if your frost line exceeds 24 inches. Check your local frost depth map — in the northern US (Minnesota, Wisconsin), frost lines can reach 48–60 inches. In the Southeast, 12–18 inches is typical. The frost line is the critical variable: a post above the frost line will heave out of the ground when the soil freezes and expands.

How much concrete do I need per post hole?

Use one 50-lb bag of fast-setting concrete (like Quikrete Fast-Setting) per hole for a standard 8-inch diameter hole at 24 inches deep. For 10-inch holes: 1–2 bags. Mix dry in the hole or pre-mix — both work. Fast-setting concrete (walk-on in 4 hours, full strength in 24 hours) is easier for fence work than standard mix because you can set all posts in a day and start rails the next morning.

What wood should I use for a privacy fence?

Cedar and redwood are the best choices — naturally rot-resistant, dimensionally stable, and hold fasteners well. Pressure-treated pine (ACQ-treated) is cheaper and more widely available — suitable for posts in contact with soil and for rails/pickets if you're on a budget. Avoid untreated pine or whitewood for outdoor fence work: it will rot within 5–8 years in contact with moisture. All posts going in the ground should be rated for ground contact (UC4B or UC4A minimum).

What spacing should I use between fence pickets?

Privacy fence: zero gap (butted together) for maximum privacy, or 1/8-inch gap to allow for wood swelling. Traditional picket fence: 2–3.5-inch gap between pickets, matching the picket width for a classic look. Semi-privacy: 1–2 inch gap. For wood that will dry and shrink after installation (green-treated lumber): use a nail as a spacer for a gap equal to the nail diameter — the lumber will shrink to fill it. Dry cedar or redwood: butted pickets maintain the joint.

Do I need a permit to build a fence?

Usually yes for privacy fences over 6 feet and in most municipalities for any fence. Check your local building department — many issue fence permits online in 1–2 business days. Also check: HOA rules (height restrictions, material requirements, color), property line setbacks (usually 2–6 inches from the property line, not on it), and utility easements. Call 811 before digging — free, required by law, and they'll mark buried utility lines within 2–3 business days.

How much does it cost to build a wood privacy fence — DIY vs hiring a contractor?

DIY wood privacy fence cost: $8–$20 per linear foot in materials. A 150-foot fence (average backyard) costs $1,200–$3,000 in materials — posts ($3–$6 each), concrete ($1–$2/bag), rails ($2–$4 each), pickets ($1–$3 each depending on cedar vs. pine). Tools: rent a post hole digger ($80–$130/day) unless you own one. Total time: 2–3 weekends for 150 feet working solo. Hiring a fence contractor: $20–$45 per linear foot installed, or $3,000–$6,750 for a 150-foot cedar privacy fence. Labor represents 40–60% of the total cost. Where contractors charge the most: rocky or clay soil (hand-digging required), slopes requiring stepped or raked fence sections, and removal of an existing fence ($2–$5/linear foot extra). DIY savings on a typical fence: $2,000–$4,000. The ROI is excellent if you have 2–3 people and a full weekend to commit.

How long does a wood fence last — and how do I make it last longer?

Wood fence lifespan by material: untreated pine: 3–7 years. Pressure-treated pine (ACQ ground contact): 15–25 years. Cedar: 15–25 years (naturally rot-resistant). Redwood: 20–30 years. Composite or vinyl: 25–40+ years with minimal maintenance. The limiting factor is always the posts — rails and pickets can be replaced, but rotten posts mean rebuilding the fence. Extend fence life: (1) Use ground-contact-rated pressure-treated posts (UC4B) for all posts, regardless of what material you use for pickets and rails. (2) Cap the top of each post — a post cap or angled cut sheds water instead of letting it pool on the end grain. (3) Apply a wood sealer or stain every 2–3 years. Untreated cedar grays attractively, but sealed cedar resists checking and splitting. (4) Keep soil and mulch 2 inches away from the base of wooden pickets — contact with soil accelerates rot. (5) Trim vegetation away from fence panels — plants trap moisture. A well-maintained cedar fence should last 20+ years.

A wood fence starts with post holes at least 1/3 the post length deep (24–30 inches for a 6-foot fence). Set posts in concrete, let cure 24–48 hours, then attach rails and pickets.

A fence you build yourself costs 40–60% less than hiring out. It takes a weekend and the right sequence.

What you need

Step 1: Call 811 and pull permits

Call 811 (or submit online at call811.com) at least 3 business days before you dig. Utility companies will mark buried lines — electric, gas, water, cable — with flags or paint.

Pull the fence permit if required in your area. For most municipalities, attach a plot plan showing the fence line location from the property boundaries.

Step 2: Layout

Drive a stake at each corner post location. Stretch a string line between corner stakes to define the fence run. This string becomes your alignment guide.

Mark post locations: Standard spacing is 8 feet between posts (matching standard rail lengths). For a strong fence in high-wind areas: 6 feet on center. Mark each post location with a stake or spray paint on the ground.

Check property line: Measure from property pins or established reference points. Set the fence 2–4 inches inside your property line — don’t assume the existing fence or your neighbor’s hedge marks the line exactly.

Step 3: Dig post holes

Dig to below the frost line or 24 inches minimum, whichever is deeper. The hole diameter should be 3 times the post width — for 4x4 posts, dig an 8–10 inch diameter hole.

Rent a power auger for more than 10 holes. A 2-person gas auger rents for $100–$150/day and turns a 2-day job into a 3-hour one.

Dig a few extra inches and add a 2–3 inch gravel layer at the bottom of each hole for drainage. This prevents water from sitting under the post and rotting it.

Step 4: Set corner posts first

Set and plumb corner posts first. All fence lines are measured from these.

  1. Place the post in the hole.
  2. Use a post level (4-way bubble level) on two adjacent faces to plumb the post.
  3. Brace with 2x4 stakes and screws to hold it plumb.
  4. Pour fast-setting concrete dry into the hole around the post (Quikrete Fast-Setting can be poured dry directly and then water added).
  5. Add water per bag instructions — the concrete sets within the hole.
  6. Let cure 24–48 hours before removing braces.

Step 5: Set line posts

With corner posts set, run a string line from corner to corner at the top of the posts. This is your height guide.

Set each line post to match the string height. Use the string to keep the post faces aligned. Plumb each post, brace, and concrete as above.

Check alignment frequently: A post 1/4 inch out of line becomes a visible gap between pickets.

Step 6: Attach rails

For a 6-foot privacy fence: use 3 rails — top, middle, and bottom. For a shorter decorative fence: 2 rails suffice.

Rail positions:

  • Top rail: 6–8 inches below the post top
  • Bottom rail: 6–8 inches from the ground (high enough to avoid ground rot)
  • Middle rail: centered between top and bottom

Attach rails to posts with post cap brackets or by toe-screwing. Toe-screwing is simpler — drive two 3-inch exterior screws through the rail face at a 45-degree angle into the post.

Step 7: Install pickets

Snap a chalk line along the top of the rails marking the finished picket height. Use this as your cut line for uniform height.

  1. Start at a corner or gate post.
  2. Set the first picket, check plumb, and screw or nail in place (2 fasteners per rail).
  3. Use a spacer block for consistent gap width.
  4. Continue along the run.
  5. Cut the last picket in each bay to fit using a circular saw.

Cut all pickets to final height with a chalk line across multiple pickets at once using a circular saw set to the right height — faster than individual cuts.

Step 8: Add post caps

Install post caps on each post top. These shed water and dramatically extend post life by preventing moisture from entering the end grain.

⏰ P2D 💰 $500–$2,000
  1. Call 811 and pull permits

    Submit to 811 (call811.com) at least 3 business days before digging — utility companies will mark buried lines with flags. Pull the required fence permit from your building department and confirm HOA restrictions, height limits, and property line setbacks before ordering materials.

  2. Layout the fence line

    Drive stakes at each corner post location. Stretch a string line between corners to define the run and mark post locations at 8-foot spacing with stakes or spray paint. Measure from property pins to confirm the fence sits 2–4 inches inside your property line.

  3. Dig post holes

    Dig to below the frost line or 24 inches minimum, whichever is deeper. Hole diameter should be 3 times the post width (8–10 inches for 4x4 posts). Rent a power auger for more than 10 holes. Add a 2–3 inch gravel layer at the bottom of each hole for drainage.

  4. Set corner posts in concrete

    Set corner posts first — all fence lines are measured from these. Plumb each post with a 4-way post level on two adjacent faces and brace with 2x4 stakes. Pour fast-setting concrete dry into the hole, add water per bag instructions, and let cure 24–48 hours before removing braces.

  5. Set line posts and attach rails

    With corner posts cured, run a string line between them at the top as a height guide. Set each line post to match the string and concrete as above. Once all posts are set, attach rails: 3 rails for a 6-foot fence (top, middle, and bottom), using post cap brackets or toe-screwing with 3-inch exterior screws.

  6. Install pickets and add post caps

    Snap a chalk line along the rail tops at finished picket height. Starting at a corner, set each picket with a spacer block for consistent gap width and fasten with 2 screws per rail. Cut the last picket in each bay to fit. Install post caps on every post top to shed water and prevent end-grain rot.

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