A leaning fence is one of the most common calls we get, especially after a spring windstorm. The good news is that a lean usually starts at one or two posts, and fixing those early can save the whole fence.
Why fences lean
- Rot at the ground. Wood posts rot fastest right at the soil line, where they stay damp. A post set on a layer of concrete ("teacupping") rots even faster. See teacupping.
- Clay soil. Colorado's expansive clay swells when wet and shrinks when dry. Over the years it can work a post loose. See posts in clay and rock soil.
- Wind. A solid privacy fence catches a lot of wind. Shallow or undersized posts eventually give.
- Something pushing on it. Drifted snow, soil piled against the boards, a heavy gate, or a tree root growing under the line.
Is the post loose or broken?
Dig a few inches of dirt away from the base of the leaning post.
- The post is solid but the whole footing tipped: it may be possible to straighten and re-set it.
- The wood is soft, dark or snapped at ground level: the post is rotted and has to be replaced. Bracing a rotted post only buys a few weeks.
Temporary fixes
If you need the fence to hold until a repair, brace the leaning section with a 2x4 angled from the top of the post to a stake in the ground, and keep pets away from it. Avoid pushing a leaning section upright by force, which can crack the rails.
Post repair spikes and metal "menders" are sold as quick fixes. They can hold a lightly leaning post that's still solid, but they don't fix rot, and in clay soil they often loosen again.
How a post should be replaced
- Support the fence panels on both sides, then take the boards and rails off the bad post.
- Dig out the old post and all of its old concrete.
- Put dirt in the bottom of the hole. Set the new post a couple of inches into the dirt and pack it tight. Never pour concrete under the post.
- Plumb the post, then pour concrete around the sides. Crown the top so water runs away from the wood.
- Let the concrete set, cut the post to height, and reattach the rails and boards.
Where wind is worst, a steel post is an upgrade worth considering.
When it's more than a post or two
If the lean is spread across many posts, or the rails and boards are rotting too, it may be time to replace rather than repair. Our repair or replace guide has a checklist. Or send us photos and we'll tell you honestly.