How to Repair a Wood Fence


Just because a section of fencing is bad doesn't mean the whole fence has to be replaced. Follow these fence repair tips.
Just because a section of fencing is bad doesn't mean the whole fence has to be replaced. Follow these fence repair tips.
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Sun, wind, rain, snow, rot, and below-ground frost subject wood fences to a terrific beating. Wood is vulnerable to nature's punishments, especially rotting. This means you should always repair fencing with the most rot-resistant lumber you can afford. Pressure-treated lumber has been saturated with preservatives and lasts almost indefinitely, even with wood that has been buried in the ground. This type of wood is expensive, however. Cedar and redwood stand up well underground and are also costly. Exterior paints and stains work well above ground but are almost useless below or on parts of fences in frequent contact with water.

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The components of a wood fence include vertical posts, rails that run horizontally from post to post, and screening material such as boards or pickets. Examine your fence, no matter what its type, and you can probably identify each of these elements.

Rot is a wood fence's biggest enemy. Posts that weren't properly treated or set in concrete typically rot away at ground level. Bottom rails and the bottoms of screening can suffer, too, especially if vegetation has been rubbing against them and trapping water. Carefully inspect fences at least once a year, paying particular attention to these areas. When you find a problem, correct it before the damage spreads. One weak post, for example, could pull down an entire fence.

The following article will tell you the steps you need to take to keep your fence in the best shape possible. It also will show you how to put up a new fence if your old one is a lost cause. Before we tell you how to build a new fence, however, we'll focus on making repairs that are much more minor. ­

Repairing Fence Rails

A wood fence doesnt have to be replaced just because its rotting.
A wood fence doesnt have to be replaced just because its rotting.

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A rail that's pulled loose from one or more of its posts may or may not be salvageable, depending on how badly rotted the joint is. You may be able to mend the break with a 2x4 scrap or a couple of metal T-braces, or you may have to ­replace the entire rail. To repair a rail with a 2x4:

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Step 1: Before you make repair, saturate the damaged areas and a 2x4 liberally with a wood preservative. This keeps the rot from spreading.

Step 2: To make a cleat to support the rail, make sure the rail is level, then fit a 2x4 snugly underneath. Nail the 2x4 to the post with galvanized nails. Drive a couple of nails down through the rail into the cleat.

Step 3: Carefully caulk the top and sides of the repair to keep out moisture.

Galvanized steel T-braces, available at most hardware stores and home improvement centers, are somewhat less conspicuous and often make a more lasting repair. To use T-braces in rail repair:

Step 1: Level the rail, then drill pilot holes into the post and rail.

Step 2: Secure the T-braces to the rail with galvanized screws.

Step 3: Caulk the joint.

Step 4: Paint the T-braces to match the fence.

Repairing Fence Sections

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If the entire rail needs to be replaced, dismantle that section of fence and rebuild it as explained below.

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Step 1: Cut 2x4 rails to fit flat along the tops of the posts. The rails can extend from post to post, or a rail can span two sections. Measure and cut each rail individually to allow for slight variations in the fence post spacing. Butt the ends of the rails tightly together. Then, beginning at one end of the fence line, nail rails in place with two 10d galvanized common nails at the ends of each rail.

Step 2: Measure and cut the 2x4 bottom rail to fit snugly between each pair of posts. Position the rails flat between the posts, anywhere from slightly above grade level to 12 inches up. Nail the bottom rails into place with a 10d galvanized nail driven at an angle through the fence post and into the end of the rail on each side. Use a level to keep rails even.

­ Step 3: Measure and cut the fence boards. They should be of uniform length, as long as the distance from the bottom of the bottom rail to the top of the top rail, as measured at one of the posts. Starting at one end, nail boards to one side of the rails, leaving space equal to a single board width between each. Secure each board to the rails with two 8d galvanized nails at the top and two at the bottom. Nail tops first, flush with the top, then nail the bottoms, pulling or pushing the bottom rail into alignment as you go. If your fence will have boards on both sides, nail up all the boards on one side first, then nail alternate boards to other side of the rails, positioning boards to cover spaces left by boards on opposite side. ­

Repairing Fence Screening

Replacing broken or rotted screening takes only a few hours and simple carpentry skills. To replace rotted screening:

Step 1: Measure the unbroken piece to get the correct length and width for new the piece or pieces you'll need. Use lumber that's the same width as the old screening, or rip boards to the proper width with a handsaw or power saw. Check all the cuts with a carpenters' square before you make them.

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Step 2: If you're replacing pickets or other curve-top screening, set cut the board against an unbroken picket and trace the top onto a new board. Make these cuts with a saber, coping, or keyhole saw. If the fence is painted, give the new screening a coat of top-quality exterior primer; for natural wood fences, stain the new boards to match.

Step 3: Remove broken pieces by hammering and prying them away from the rails. Pull out any nails.

Step 4: Set the new board or picket against the rails, align it, and nail it firmly into place with galvanized 8d nails.

Step 5: Paint new pieces to match the rest of fence.

Replacing broken or rotted screening takes only a few hours and simple carpentry skills. To replace rotted screening:

Step 1: Measure the unbroken piece to get the correct length and width for new the piece or pieces you'll need. Use lumber that's the same width as the old screening, or rip boards to the proper width with a handsaw or power saw. Check all the cuts with a carpenters' square before you make them.

Step 2: If you're replacing pickets or other curve-top screening, set cut the board against an unbroken picket and trace the top onto a new board. Make these cuts with a saber, coping, or keyhole saw. If the fence is painted, give the new screening a coat of top-quality exterior primer; for natural wood fences, stain the new boards to match.

Step 3: Remove broken pieces by hammering and prying them away from the rails. Pull out any nails.

Step 4: Set the new board or picket against the rails, align it, and nail it firmly into place with galvanized 8d nails.

­ Step 5: Paint new pieces to match the rest of fence.

Repairing Fence Posts

Dig out around a loose post and fill it in with concrete.
Dig out around a loose post and fill it in with concrete.
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When a post begins to wobble, determine the cause before you make the repair. If the post is rotted or broken, you may be able to repair it with a pair of splints or you may have to replace the entire post.

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If the post seems intact but has come loose in its hole, a pair of stakes or, better yet, a new concrete base can steady the post. To stake a post:

Step 1: Select a pair of 2x4s long enough to reach below the frost line for your region and that extend at least 18 inches above ground. Use only pressure-treated lumber, cedar, or clear all-heart redwood.

Step 2: Bevel cut one end of each 2x4, and drive them into ground along opposite sides of post.

Step 3: Bore two holes through both 2x4s and the post, then bolt everything together with galvanized carriage bolts.

­ For a more permanent cure, dig out around the post, plumb it with temporary braces, and pour concrete around the post's base. Prepare premixed concrete, stir it well, and pour it into the hole around the post. Slice the concrete mix periodically with a spade as you pour to eliminate any air pockets. At the top of the hole, mound concrete around the base of the post to shed water.

Repairing Fence Gates

Straighten a slightly sagging gate by removing the screws from the bottom hinge and shimming it with a cedar shingle.
Straighten a slightly sagging gate by removing the screws from the bottom hinge and shimming it with a cedar shingle.
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When a gate sags or won't close properly, the first thing you should do is check its hinges. If they're bent, replace them with a heavier type of hinge. If the hinge screws are pulling loose, remove them and plug the holes by gluing in short pieces of dowel.

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Then drill new holes and install longer screws or carriage bolts. Use only galvanized steel hardware.

With a gate that's sagging only slightly, you may be able to straighten it up by shimming under the bottom hinge. Prop the gate open, remove the screws from the post side of the hinge, and cut a thin piece of cedar shake to fit into the hinge mortise. Reattach the screw by driving longer screws through the shim.

Sometimes a gate sags because its own weight has pulled it out of alignment with the fence. One quick way to square up a gate is to drive a screw eye into the upper corner of the gate on the hinge side and another into the lower corner on the gate side.

Run wire and a h­eavy-duty turnbuckle from one screw eye to the other, and tighten the turnbuckle until the gate frame is square.

What if your fence is beyond repair and you need a new one? We have that covered, too. Read the next page to find out how to build a wood fence.

Replacing a Wood Fence

Dig postholes with one of several types of diggers­.
Dig postholes with one of several types of diggers­.

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The hardest part of building a new fence is digging the holes for the posts. For this you'll need a posthole digger. Hand-operated clamshell and auger diggers work fine in sandy, rock-free soil. If your soil is rocky or you have a lot of holes to dig, rent a power-driven auger.

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For best results, use pressure-treated, ground-contact lumber, cedar, or redwood. With the latter, no finishing is necessary; the fence can be left to weather naturally. If you must, you can use untreated wood for screening and top rails, and for bottom rails that are at least four inches above the ground.

You'll need 4x4s for fence posts, 2x4s for rails, and 1x4s or 1x6s for screening. To build a fence:

Step 1: Lay out the approximate fence line, making sure you're not on your neighbor's property.

Step 2: Establish the exact location of the first end or corner post. Dig a hole there that's 18 to 24 inches deep. For a fence that's five or six feet high, dig down 24 inches.

Step 3: Pour about three inches of gravel into the bottom of the hole to improve drainage, then set the post into the hole.

Step 4: Level the post. Then brace it in two directions with wooden stakes.

Step 5: Prepare premixed concrete, stir it well, and pour it into the hole around the post. Slice the concrete mix periodically with a spade as you pour to eliminate any air pockets. At the top of the hole, mound concrete around the base of the post to shed water.

Step 6: After the first post is set, determine exactly where you want the opposite end or corner post. Set this post the same way you set the first one. Only end, corner, and gate posts need to be set in concrete. Intermediate posts usually can be set in soil.

Posts must be absolutely plumb (vertical). To plumb a post, set it in in its hole, hold a level to one side, and adjust the post until the level's bubble is exactly centered.
Posts must be absolutely plumb (vertical). To plumb a post, set it in in its hole, hold a level to one side, and adjust the post until the level's bubble is exactly centered.

Step 7: To set intermediate posts, measure the height of each end post above grade level to ensure that both are the same height. Drive a nail partway into each post, facing the direction of the fence line, just above ground level. Tie a piece of twine to one nail, stretch it to the other post, and secure it to the other nail. Using the string as a guide, drive stakes to locate the intermediate postholes. Posts are usually spaced eight or ten feet apart. Remove the string and nails after you've driven the stakes.

Step 8: Dig holes for the intermediate posts.

Step 9: Pour about three inches of gravel into each hole. Set a post into each hole and use the twine as a guide for checking the post's height. If necessary, make height adjustments by varying the depth of gravel in each hole or shimming up the posts with stones.

Step 10: Set each post and plumb it (make sure it's perfectly vertical), then fill in around its base with about six inches of gravel. Fill up the rest of the hole with soil, shoveling in about four inches at a time and compacting each layer with a scrap of 2x4.

Step 11: Cut 2x4 rails to fit flat along the tops of the posts. The rails can extend from post to post, or a rail can span two sections. Measure and cut each rail individually, to allow for slight variations in fence-post spacing. Butt the ends of the rails tightly together. Then, beginning at one end of the fence line, nail the rails into place, using two 10d galvanized common nails at the ends of each rail.

Step 12: Measure and cut a 2x4 bottom rail to fit snugly between each pair of posts. Position the rails flat between the posts, anywhere from slightly above grade level to 12 inches up. Toenail the bottom rails into place with a 10d galvanized nail driven through the fence post and into the end of the rail on each side. Use a level to keep the rails even.

Step 13: Measure and cut the fence boards. The boards should be of uniform length, as long as the distance from the bottom of the bottom rail to the top of the top rail, as measured at one of the posts. Starting at one end, nail the boards to one side of the rails, with a space equal to a single board width between each; use a board as a spacer as you work. Secure each board to the rails with two 8d galvanized nails at the top and two at the bottom.

Nail the tops first, flush with the top, then nail the bottoms, pulling or pushing the bottom rail into alignment as you go. If your fence will have boards on both sides, nail up all the boards on one side first, then nail alternate boards to the other side of the rails, positioning the boards to cover the spaces left by the boards on the opposite side of the fence.

Now you possess enough knowledge to repair your fence, whether it needs minor fixes or must be rebuilt altogether. ­

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