Repairing fence rails
Rails seldom deteriorate along the middle of a fence bay. Any damage they sustain usually occurs at an end. That’s where rot begins—more often on the bottom rail than on the top because moisture collects on the fence and runs down and evaporates up from the soil. The bottom rail also tends to be more sheltered and is not able to dry out as quickly as the top rail.
One of the first signs of rail damage is loose fasteners. Before you rip off the rail, try resetting loose nails. At best this will probably turn out to be a temporary fix, because by the time you realize the fasteners are loose, the stress on the joint has probably enlarged the hole and removed enough wood fibers that the nail is left with nothing to grip.
If the rail works loose again after a couple of days, try removing the nails and refastening the rail with 10×4-inch coated screws (or screws that will be long enough to reach into fresh wood without going through the other side). As a last resort you can support the rail with several braces. These braces also are likely to be temporary—if a new fastener won’t hold the rail in place, it’s a pretty good bet that the rail harbors some other form of structural problem and needs replacing. Bracing, however, will buy you some time, even though you may not consider it the most aesthetically appealing solution.
Removing and replacing a rail may take you an hour, but it won’t take a great amount of energy. The most time-consuming aspect of this job is getting all the fasteners out. If the infill is fastened with nails, don’t try to pry them out without first working from the backside of the fence to pry the infill away from the frame. Then go around to the front side of the fence and tap each infill board back on the rail. The board should move but the nail should not, leaving its head exposed. When you pry out the nails, slip a piece of lx scrap under the hammerhead—it will increase your leverage and keep the wood from denting. Before you remove the rail, mark its location so you know where to put the new one.
Removing the rail does not require much finesse because it’s damaged anyway. Don’t try to pry it out—you may tear up the post. If it’s screwed in place, remove the screws. If it’s nailed give one end a couple of solid blows with your hammer (or small sledge), and it should fall away with the nails intact. Pull the rail from the other end with a twist. You can also cut through it near the middle and wrest the two ends free.
A sagging fence bay may be an indication that gravity has gradually taken its toll, and the weight of the infill is more than the rails can support and remain level. This is a problem you might be able to remedy by jacking up the center of the bay with a hydraulic jack (just under the edge of the bottom rail) and installing a 2x kickboard. However, a sagging bay may also be an indication of serious post damage. If damaged posts are the problem and replacing the entire fence is not feasible, you can add a post in the center of the affected bay(s).
Mark the center of the bay and locate the new posthole. You can’t center a clamshell digger on the hole because the fence is in the way, but you can come close, digging most of the hole with the digger and enlarging it from the other side with a round-nose shovel. Once you’ve dug the hole, you can set the post in it and mark the post for the location of the notches.
It’s not critical at this step that the notches in the post are at exactly the precise height. What is critical is that their spacing is the same as the rail spacing and that the notches in the rails are plumb with each other, which will keep the post plumb when you set it.
What kind of notch you cut will depend on whether the rails are set flat or on edge. You can notch the post with a circular saw, cutting kerfs and chiseling out the waste. The circular saw will also work when notching the rail, but the weight of the saw might make it difficult to work with when holding it upright. Using a jigsaw (and the same kerfing technique) will make this cut easier. Just make sure you cut the kerfs to the same depth.
When you set the notched post in the ground, tap it into the notches and tack it to the rails from the back of the post. You can level the rails with your method of choice. A hydraulic bottle jack is shown, but most screw jacks made for changing tires on cars will work also.
If you don’t have a suitable jack, have a helper level the bay with a tamping bar levered on wood blocks. Keep the bay level with another set of blocks while you backfill the hole. Whatever device you use to level the bay, leave it in place until the concrete cures. When the concrete has set, strengthen the notches with additional fasteners.
If a post is rotted below ground and the above ground section is sound, you can replace it with a new one or shore it up. Although shoring up a post is a repair that can last a long time, the repair will be obvious, and you may find its appearance distracting, such that replacing the post is the way to go. It essentially returns the fence to its original form. In any case, if the visible section of the post is damaged, you should replace it. A post replacement requires stripping the infill from the bays on each side of the post and removing the rails. Because you’ll want to reuse all this lumber, exercise some care when taking the bays apart. Slip a short length of scrap wood under your hammer, pry bar, or cat’s paw when prying up nails. The scrap will give you a little more leverage and protect the surface of the wood. Loosen the infill from the backside of the fence before pulling nails. If the fence is assembled with screws, make sure you remove all of them before taking a board down. Any screws that were over driven when the fence was built may look like empty holes. When you try to remove a board that’s still partly fastened, you’ll rip the wood.
Pulling posts from the ground can be difficult work. You’ll most likely have to dig to at least two-thirds of the depth of the post and usually to the bottom—at least on one side of it. No matter how much soil you remove, work the post back and forth before pulling it out. If the post breaks at the rotted section, you may have to dig it out in pieces, using a tamping bar to break it apart.
Shoring up a damaged post
Shoring up a damaged post can provide a permanent repair if done correctly. For success most of the above ground surface of the post must be damage-free. Before you start this job, support the post with temporary braces. That way you won’t damage fasteners or the rest of the frame when you cut away the damaged section.
The most difficult part of this job is removing the concrete around the post. Not too long ago traditional post-setting methods called only for a concrete collar to keep water out.
Removing a collar will take a bit of time, but most will come away if you crack them with a cold chisel. You may even be able to crack the collar with a sharp blow from a small sledge. A hammer drill equipped with a cold chisel will also do the job. Wear eye protection when hammering or chiseling concrete.
If the post is set in a concrete footing, you won’t be able to crack it. You will have to dig out the footing instead.
At some point in this process, you’ll have to cut the post—when you do it is a matter of preference and the requirements of the job at hand. Whenever you cut the post, use a reciprocating saw and cut it a couple of inches above ground.
Brace the damaged post to keep the fence from sagging when you cut away the rotted section. Break up any concrete collar with a small sledge and cold chisel, remove it, and dig out around the post. If the post is set in a concrete footing, don’t try to break it up; dig around the footing. Cut the post above the rotted section and remove it and any footing. Enlarge the hole to accommodate the new post section.
Cut a new stub post, then shovel about 4 inches of gravel into the hole and set the stub post in. Plumb it and brace it as necessary (you may not need the braces on this short a post) or clamp it to the old post if it’s plumb. Then fill the hole with tamped concrete. Let the concrete cure. You can drill the holes in the new post before you set it in the hole or after the concrete sets up.
Straightening a leaning fence
Even a well-constructed fence can develop a lean over time. Strong winds and heavy rains can cause it to lean, as can poor soil conditions. And of course a fence with improperly set posts will eventually lean due to its own weight, no matter what. Bringing a leaning fence back to plumb is not difficult, but it does take time.
The key is digging on the backside of the leaning post sufficiently to provide space in the ground to move the post back to vertical. You’ll need to dig down to at least two-thirds of the post depth to give it the freedom it needs. If you leave the excavation short, the bottom of the post will have to move against solid ground, and that risks snapping it. Concrete post footings increase the difficulty of removing the soil and straightening the post, but they don’t make it impossible.
There are no specific guidelines or rules for determining how deep to dig. On site field experience is the best guide; you’ll know when you try to move a post whether you have dug deep enough. If you get to a point where one or more posts are almost, but not quite, plumb, loosen the braces, dig a little deeper, pull the fence back again, and re brace it. With patience, and by working one step at a time, you’ll be able to reset the fence exactly as it should be. When you’re pulling the posts, you’ll hear the fence creak, but if you hear sharp snapping noises, stop and dig some more.
A fence seldom leans in only one bay, so in most cases you’ll have more than one post to straighten. Dig around all leaning posts—plus one more, even if the additional one is straight. Pulling the errant posts back into position may leave the next post over corrected. Excavating this post will avoid this problem and allow the fasteners a little more give.
In most cases you’ll have to work up and down the leaning section more than once. Trying to straighten the fence in one move puts too much strain on the wood, and you may end up with a broken rail. That way you can move back and forth along the line without having to reset the pipe.
To straighten a fence section, start by enlarging the posthole opposite the side that is leaning down. Dig to the base of the post if possible, but at least two-thirds of the post depth. In most cases a leaning fence will be caused by more than one errant post—enlarge the holes of all posts that are not plumb. If the posts are set in concrete footings, enlarge the holes on all sides of the footings and dig to the bottom so you can move the footing along with the post.
Fixing sagging gateposts
Gateposts are the hardest-working parts of a fence. The hinge post supports the weight of the gate and, in some situations, the added weight of young people swinging on it. If the hinges hold, all this abuse is transferred to the post. Both posts absorb the shock of the gate slamming shut thousands of times.
Gateposts sag into the gate opening or perpendicular to it, sometimes both, and not always just on the hinge side. If the post leans into the opening, you may be able to pull it back into place with a sag bar—a kit that includes a turnbuckle, a pair of threaded rods, and fasteners. In many cases pulling the post back with a sag bar will also pull it off plumb at right angles to the fence.
To straighten a post leaning perpendicular to the fence, you must dig around the post to give it space to move. This means digging down to at least two-thirds of the depth of the post. If the posts are set with concrete collars, break the collars up and remove them with a cold chisel and small sledge. If they’re set in concrete footings, don’t break up the footings—enlarge the hole by about one-third of its width and excavate to the bottom of the footing. If you find a rotted base when you dig, you’ll have to replace the post. To keep the post from sagging in the future, shore it up with a concrete base. Excavating a trench between the posts and pouring concrete will create a solid base that helps anchor both posts.
A sagging gate can be caused by any number of failures in the gate system. Over time the gate may fall out of square, or its hinges can become loose or bent. The longer you let the problem go, the more damage the gate will incur. It is better to fix a minor problem as soon as you discover it than to have to rebuild and replace the gate entirely.
The most common gate problem is loose hinges, or more specifically, loose hinge fasteners. Before repairing the fasteners, however, take a close look at the hinge pins. Grab the gate by the top rail on the latch side and move it slowly up and down. Watch the hinge pins as you move the gate. If they move back and forth or if the fingers of the hinge rock against each other, the hinge is too worn for further use. Then look for bent hinges—a sure sign that the hinges are too small or are not positioned correctly on the gate or post. Gates that are more than 5 feet high or 3 feet wide need to be hung on three hinges—two won’t do.
Replace all the hinges even if only one is worn or bent. One worn hinge means that the other has been working overtime and is soon likely to exhibit the same effects. When you install the new hinges, take a little extra time and mortise them into the posts and gate frame. Mortising transfers more stress to the entire frame and lightens the load placed on the hinges and fasteners. When hinge screws have worked loose, it’s usually too late to try to tighten them. By this time the screws have probably worn away too much wood, and they won’t hold if you do tighten them.
You can move the hinges to a new position on the gate and post (and thus fasten them into fresh wood), but that can disrupt the balance of the gate as well as its aesthetic appeal. Instead remove the hinge pins and the gate and then remove the hinge fasteners from the gate and the post. Drill out the fastener holes and drive in glued dowels. The dowels provide a strong medium into which to drive the screw. If you replace the screws with longer ones, make sure the head seats properly in the recess of the hinge plate. A protruding screw head will come into contact with the other hinge plate and stress the gate when you try to open it.
If your gate is large and the hinges too small, you may want to increase the size of the hinges and use machine bolts to support them. A racked (out-of-square) gate will show up with any number of symptoms. It may bind, the latch may work hard or not at all, and the vertical members of the gate frame may appear angled to the rails. All of these problems can be fixed by squaring the gate and reinforcing it so it stays that way.
The first step in reshaping the gate is to set a framing square on an outside corner and apply pressure with a clamp on the opposite diagonal. Tighten the clamp until you can’t see any “daylight” between the gate frame and both edges of the framing square. Keep the corners square by tacking a lx brace on an opposite corner.
If the gate is square but binds when the weather is wet, plane wood off the latch side so it clears the post. Gates should typically have at least Vi inch of clearance between the frame and the latch post to allow for expansion. If the latch binds in any kind of weather, change the placement of the latch or striker. And if the gate shrinks in dry weather to a point that the latch won’t catch, relocate the latch or replace it with one that has a longer reach.
In some cases, especially with a heavy gate, it’s a good idea to replace hinge screws with a hefty hinge and bolts. The heads and nuts of machine bolts can sit on top of the face offence framing, but they will look dressier if you put them in counter bores. Make sure the counterbored recess is wide enough to accommodate a socket wrench and deep enough to accommodate the thickness of the nut and a washer (plus a lock washer if you use one). Tighten the nut until it’s snug, then a half-turn more.