How to Fix a Fence
Time Required: Over 1 day
All good fences need periodic maintenance to keep them functioning properly and looking their best. When faced with damage, the first decision is whether to repair or replace. Armed with the tips shown in this guide, you can make a fence as good as new with minimal need to replace sections.
Begin by removing any parts that get in the way of the repair. You can either remove the fencing with a pry bar or cut out the damaged section with a handsaw. When repairing a post, remove the fencing and rails connected to it. Once the repair is complete, use new nails when replacing fencing and rails.
This guide highlights repair and maintenance projects to tackle that will keep your fence looking good and functioning properly, including cleaning your fence, repairing buried rot, fixing posts that lean, making repairs to a chain-link fence and more.
Scrub wood fences with a fiber scrub brush and a mild detergent solution to remove most stains. For tougher stains, add 1 to 2 cups of bleach to a bucket of warm water. Wear gloves and safety glasses when working with strong cleansers.
Clean vinyl fences with a sodium-bicarbonate-based cleaner. Bleach may stain the fence. Use a cloth instead of a brush so you don’t scratch the surface of the fence. Wear safety glasses.
Clean metal fences with a wire brush, scrubbing away old paint, dirt, and rust from metal posts, hardware, and other areas. You can take care of most stains with 1 cup of strong household detergent mixed with a gallon of warm water.
Finally, rent a pressure washer for hard-to-reach crevices in basket-weave and other fences or for stubborn stains on vinyl fences. Spray about 6 to 10 inches away from the fence. Don’t use more than 1,000 PSI of water pressure or the force may damage the wood. Many companies make commercial deck cleaners that are also good for cleaning fences. Consult the manufacturer’s instructions before starting.
Reinforce rail ends with 2 x 4 cleats fastened to the posts. Screw the cleats in place with #8 deck screws or nail with galvanized 10d 3-inch nails. Taller fences often have third rails in the center, which can be reinforced using this method as well.
Add a sister rail to bolster a damaged rail. The sister rail can span the entire original rail or just part of it, depending on the damage. Clamp the sister rail under or on top of the original, then drill holes through both rails, bolt them in place with 3/8 × 4-inch carriage bolts, and remove the clamps.
Add a third rail between the top and bottom rails. If the fencing seems loose, screw the rail to the posts with #8 deck screws or toenail with galvanized 10d 3-inch nails. Fasten the fence boards to the new rails with #8 deck screws.
Remove the fence boards from the damaged rail. Unscrew the boards, as shown here, or pry off the boards and pull out the nails. Try not to damage the fence boards so you can reinstall them later.
Next, remove the rail by prying out the nails or removing the hardware holding the old rail in place. Cut a new rail to fit between the posts. Nail or screw the rail in place, and then reinstall the fence boards.
Lastly, save yourself some work when you need to replace a short section of rail on a fence that has an exposed rail by splicing a new piece of rail in place. Remove the boards from the damaged section of rail, and then cut off the damaged section at an angle. Put the new piece in place alongside the cut and trace along the cut in the old piece to transfer the angles to the new piece. Cut along each line, drill holes, and bolt the new piece in place with 3/8 × 4-inch carriage bolts.
Next, plumb the fence by screwing braces to the post, plumb it with a level, and then screw the braces to stakes driven in the ground. Check again for plumb and reset the braces if necessary.
Lastly, pour a new concrete footing from pre-mixed bagged concrete, following the directions on the bag. The consistency should be about as thick as oatmeal. Fill the posthole with the mix, sloping the concrete away from the posts for drainage.
You can also reinforce a damaged post with a small post called a sister post. A sister post is half the thickness of the original post and the same width, but no higher than the fence’s top rail. Cut the base of the sister post at a steep angle so you’ll be able to drive it in like a stake. Put it in place against the original post. Place a block on top of the sister post to avoid splitting it in two. Hit the block with a 3-pound sledgehammer to drive it 2 to 3 feet into the ground. Bolt it to the original post with 3/8 × 4-inch lag screws. Using a handsaw, cut a 45-degree angle on the top of the sister post so it will shed rain.
Begin by digging around the footing to remove the soil around the damaged post. Dig deep enough to reach the bottom of the post or concrete. If a post has rotted in the ground, you can put a second, shorter post next to it and tie the two together.
Then, cut off the old post just above the damaged part and pull the bottom section out of the ground. Cut a new post section 1 foot or so longer than the section you removed, and bevel the top. Place the new section in the hole next to the undamaged part of the original post.
Clamp the two post sections together. Counter bore 1-inch holes for the heads of carriage bolts, drill ½ inch through holes, and insert ½-inch carriage bolts with washers. Put washers and nuts at the other end of the bolts and tighten with a socket wrench.
Lastly, fill the posthole with new concrete. Slope the top to help drain water away. Let the concrete harden for two to three days before removing the braces and supports.
Loosen the mesh by removing the tie wires from the mesh with pliers. Connect a fence puller to both the post and fence and draw the fence tight enough to take tension off the tension bar. Remove the tension bar by loosening the bolts in the tension band. Loosen and remove the fence puller.
Remove the damaged section by opening the loop at the top and bottom of a strand just outside the damaged area. Twist and pull the strand free. Take out a strand on the other side of the damage and remove the damaged section.
Next, cut a section of mesh the same size as the one you removed. Weave it into the remaining fence using the strands you removed earlier. Loop the wire at the top and bottom of the strand back around the fence with pliers.
Attach a fence puller by sliding a pull bar through the mesh about 4 feet from the end post. Crank the bar until the strands in the mesh-links flex no more than 1/4 inch when you squeeze them together.
Lastly, re-tie the patched fencing to the posts and attach new tie wires to hold the mesh firmly against the top rail and line posts. Thread a new tension wire through the bottom openings in the mesh.
If a gate droops and you don’t have diagonal cross braces, install an anti-sag kit, which includes a turnbuckle, some cable and some eye hooks. Screw an eye hook into the corner on the hinge side and a second eye hook in the lower corner on the opposite side. Attach the turnbuckle and tighten to remove the sag.
If a chain link gate gets out of alignment, you can usually fix it by adjusting the hinge pins. Loosen the pins with a socket wrench and reposition them with a wood block and hammer. Check the gate’s swing and reposition, if necessary, before tightening.
And finally, when a gate swings too far, that means the hinges are loose. The low-tech solution is to screw a 1 × 2 or 2 × 4 stop to the gatepost so the gate stops when it’s flush with the fence. The high-tech solution is a hydraulic gate closer, which gently pulls the gate shut and stops it at the right point.
Finish by mixing bagged concrete with water and pour the new footings. Slope the concrete away from the posts so water will drain away. Remove the braces after the concrete has hardened, in about 48 hours.