How to Repair a Wooden Fence: Replace Pickets, Rails & a Leaning Post

Planning Your Fence Repair

Before buying materials or pulling nails, do a thorough inspection of the entire fence line. Walk slowly along the fence on both sides, looking for rot at the base of each post (poke with a screwdriver to confirm), loose or broken rails, cracked or missing pickets, and any sections that lean. Measure the spacing between posts (standard is 6 or 8 feet) and note how rails are attached—whether they are nailed to the face of the post or fit into notches. Make a sketch or take photos for reference.

Determine how many linear feet of rail and how many pickets you need. A typical 6-foot fence section with 6-foot post spacing uses two 6-foot rails and about 15 pickets (assuming 5.5-inch-wide pickets with a 1/4-inch gap). You'll likely be replacing only a portion, so measure exactly. Pressure-treated lumber from a local home center is suitable; buy it a few days in advance and let it acclimate to your yard's humidity—this minimizes warping after installation.

Choosing Materials

For posts, use ground-contact-rated pressure-treated 4x4s. For rails, standard 2x4 pressure-treated lumber is adequate. Pickets come in various styles; dog-eared (with two rounded top corners) are common and easy to align. Use exterior-rated screws: coated deck screws or stainless steel for best corrosion resistance. 3-inch screws for post-to-rail connections, 1.5-inch screws for picket-to-rail. A package of 5-6 pounds of each is a good start.

For concrete, a fast-setting post mix (like Quikrete) requires no mixing—just pour dry into the hole and add water. Add a few inches of gravel at the bottom of the hole to promote drainage and prolong the post's life.

Tools and Prep

You'll need: cordless drill/driver with bits, circular saw or reciprocating saw (for cutting rails and removing old fasteners), level, tape measure, shovel or post hole digger, hammer, safety glasses, work gloves. A string line or mason's line helps align tops and gaps. A workpiece to use as a spacer (scrap picket) keeps gaps consistent.

Removing the Leaning Post

The leaning post is typically the worst offender. Dig around it with a shovel or post hole digger. If set in concrete, break up the concrete with a heavy sledgehammer or use a digging bar. Sometimes you can rock the post back and forth to loosen the soil. If the post is rotted at the base, it may snap off; in that case, dig out the stump as best you can. Clear the hole to at least 12 inches wide and 24-30 inches deep.

Setting the New Post

Place a few inches of gravel in the hole. Position the new 4x4 post, use a level to plumb it on two adjacent sides, and temporarily brace it with wooden stakes and screws. Mix post-setting concrete per instructions (or pour dry and add water) and fill the hole, tamping to eliminate voids. Slope the top away from the post for drainage. Re-check plumb and adjust within 10 minutes. Allow concrete to cure as directed—often 24-48 hours before attaching rails. If you set the post too high or low, correct height now: the top should align with other posts or be cut to height later.

Installing Rails

Once the post concrete has set, cut new rails to span between the two sound posts (or from the new post to an adjacent sound post). For face-mounting, hold the rail flush against the post side at the correct height (typically mid-height of the picket and near the top and bottom). Use a long level to ensure the rail is horizontal, then drive 3-inch screws through the rail into the post—two per post end. If the original fence used notched rails, you'll need to notch the ends of the new rails. Mark the notch depth (usually 1.5 inches) and width of the post, cut multiple passes with a circular saw, and chisel out the waste. Then drop the rail into the notch and screw through the post face into the rail.

Installing Pickets

Attach the first picket flush with the outside of the end post. Use a level to get it plumb, then drive two 1.5-inch screws at each rail location. For the next picket, use a spacer (e.g., a scrap of furring strip or another picket) to maintain a uniform gap of about 1/8 to 1/4 inch. Continue across the section, checking plumb every few pickets and aligning the tops. For longer runs, use a string line as a top guide. If the ground slopes, you may need to step pickets down; cut each picket bottom to match the slope.

Finishing Touches

If you removed undamaged pickets, reattach them with new screws. Check all screws are driven flush and pickets are secure. Trim any uneven tops with a circular saw and a straightedge guide. Finally, apply a wood preservative or stain to all new lumber. Pressure-treated wood weathers to gray if left untreated, but a clear or semi-transparent stain will extend the life and unify the color with the older wood. Let the new wood dry for a few weeks before sealing.

Safety

Wear safety glasses when cutting, drilling, or using a hammer. Hearing protection is recommended for power saws. Use gloves when handling pressure-treated lumber (the preservative can irritate skin). When digging, watch for buried utility lines—call 811 before you dig. Follow manufacturer instructions for concrete mix; avoid skin contact with wet concrete. Use proper lifting technique when handling heavy posts and bags of concrete. Keep children and pets away from the work area.

Mistakes to Avoid

1. Setting posts too shallow – leads to leaning and frost heave. Always dig below frost line and set in concrete.
2. Not allowing concrete to cure fully – attaching rails too soon can shift the post. Wait at least 24 hours.
3. Overdriving screws – can strip the head or weaken the board. Drive until snug, then stop.
4. Skipping the gravel base – water pooling around wood accelerates rot.
5. Mixing new wood with old without sealing – color mismatch is obvious; stain new wood to match.

With these steps, your fence repair will be sturdy and long-lasting, restoring both function and curb appeal in a weekend.