A fence is only as secure as its weakest point, and on most properties that point is the strip of ground where the fabric meets the soil. Learning how to secure the bottom of a chain link fence matters because a gap of four or five inches is enough for a determined dog to get out, a coyote or raccoon to get in, and a person to lift and slip under without touching a gate.
The good news is that this is a repair, not a replacement. This guide covers why the gaps form, the eight methods for closing them, how to choose between them, and how to secure fence posts when a moving post is the real cause.
Why Gaps Form Under a Fence
Understanding the cause determines the right fix. Closing a gap without addressing why it opened means doing the work twice.
Soil settling. Backfill around posts and along a fence line compacts over the first few years, dropping grade below the fabric.
Erosion and runoff. A downspout, a driveway edge, or a natural drainage path will scour a channel under a fence surprisingly fast.
Digging. Dogs dig at the fence line because that is where the interesting smells are. Once a low spot exists, they return to it.
Grade changes. On sloped ground, chain link is installed either following the contour or stepped in sections. Stepped installations leave triangular gaps under each step by design unless they are addressed.
Frost heave. Chicago winters push shallow footings upward, and posts that move take the fabric with them, opening space below.
Loose or missing bottom tension wire. Chain link is meant to be tensioned at the bottom. Without that, the fabric flexes outward under pressure.
If the fence is also leaning, rusting at the base, or has fabric pulling away from posts, the bottom gap is a symptom of a larger problem and calls for fence repair rather than a patch.
How to Secure the Bottom of a Chain Link Fence
1. Bottom tension wire
A heavy gauge galvanized wire runs the length of the fence at the base, woven through the bottom of the fabric and tensioned between terminal posts. This is the standard method and the one most missing from budget installations. It costs little, is nearly invisible, and stops the fabric from flexing outward when a dog pushes on it.
Tension wire handles pushing well and digging poorly. It keeps the fabric in place, but nothing stops an animal from excavating below it.
2. Bottom rail
A horizontal rail at the base, matching the top rail, gives the fabric a rigid edge. It is stronger than tension wire, resists pushing and lifting almost completely, and looks intentional rather than like an add-on. It costs more and requires the ground to be reasonably even, since a rigid rail cannot follow an undulating grade.
3. Ground stakes and anchor pins
J-shaped or U-shaped steel stakes drive through the bottom of the fabric into the soil at regular intervals. This is the fastest and cheapest fix, and it works well for moderate pushing.
Stakes are not a long-term answer in loose soil, and a persistent digger works around them. Space them closer than the packaging suggests, particularly in corners where dogs concentrate.
4. Landscape timbers, pavers, or a stone border
Laying pavers, timbers, or stone flat along the fence line gives an animal a hard surface to hit instead of soft dirt, finishes the line cleanly, and simplifies trimming. The weakness is at the edges, since a dog that starts digging six inches out simply tunnels beneath, so the border needs real width to work.
5. Concrete mow strip or footer
A continuous concrete strip poured along the fence line, with the fabric embedded or tension wire tied into it, is the most permanent option. Nothing digs through it and nothing pushes under it. It is also the most expensive and least reversible, which makes it the right call for commercial properties, kennels, pools, and any site where containment is not optional.
6. Buried fabric extension
Extending fence fabric below grade, typically eight to twelve inches, stops digging directly. It works, with one caveat worth knowing. Galvanized fabric in constant contact with soil corrodes faster than fabric above grade, especially where road salt reaches the fence line. Vinyl-coated fabric holds up considerably better below grade than bare galvanized.
7. L-footer or apron
Rather than burying fabric straight down, an L-footer bends wire mesh outward at a right angle and lays it flat on the ground inside the fence, staked and covered with soil, mulch, or gravel. Grass grows through it within a season. This is the most effective anti-digging method short of concrete, because dogs dig at the base of a barrier rather than backing up two feet to start, and twenty-four inches of apron stops nearly all of them.
8. Hardware cloth or small-gauge mesh
Standard chain link mesh openings are large enough for puppies, small breeds, cats, and rabbits to pass through even with no gap at all. Attaching a band of smaller-gauge mesh or hardware cloth along the bottom two feet closes those openings and doubles as a dig barrier when combined with an L-footer.
Choosing the Right Method
Match the method to the actual problem:
Dog pushes under but does not dig: tension wire or a bottom rail.
Dog actively digs: L-footer apron, or concrete for a committed digger.
Small pet slips through the mesh: hardware cloth along the lower section.
Wildlife getting in: L-footer apron plus small-gauge mesh.
Security concern on a commercial site: bottom rail plus a concrete footer.
Erosion channel under one section: fix the drainage first, then backfill and add pavers.
Gaps under a stepped installation on a slope: pavers or timbers fitted to each step.
How to Secure a Fence Post
Loose fence posts are the root cause behind a large share of bottom gaps. A post that rocks lets the fabric move with it, and no amount of staking at the base will hold a fence that is moving above it.
Fence posts loosen for three reasons. Footings set above the frost line lift during Chicago winters and never fully return, leaving the post loose in an oversized hole. Water pooling against a post, common where a concrete collar was poured flush, corrodes the steel at grade. And undersized footings on end and corner posts gradually tilt under years of tension load.
To secure a fence post properly, excavate it, set a new footing below the frost line, and crown the concrete so water sheds away rather than pooling against the post. Let it cure fully before re-tensioning the fabric. Terminal posts need larger footings than line posts because they carry the tension of the entire run. Packing gravel or dirt around a heaved post buys a season at most.
If several posts along a run are loose or the fabric has stretched, replacement of that section is often less expensive than repeated repairs, and it is worth pricing chain link fence installation for the affected run before committing to another round of patches.
Do Not Forget the Gate
Gates are the most common escape point on an otherwise secure fence. They need ground clearance to swing, which means a deliberate gap exists by design, and that gap widens as hinges wear and gate posts settle.
Options include a gate stop threshold, a paver or concrete pad under the swing path, a bottom sweep, or adjusting the gate to sit lower where clearance allows. If the gate has dropped and now drags or sits crooked, the gate post has moved and needs attention, which falls under gate installation and repair rather than a bottom fix.
What Not to Do
Do not pile loose dirt or mulch against the fabric. It holds moisture against the steel and accelerates rust at exactly the point where the fence is already weakest.
Do not use chicken wire as a dig barrier. The gauge is too light to survive burial, and it rusts through in a season or two.
Do not stake into soil without checking for utilities. Irrigation lines, low-voltage lighting, and invisible fence wire commonly run along fence lines.
Do not close the gap without fixing the drainage that caused it. Water will find the new low point.
If bare metal is exposed at the base of posts or rails during any of this work, it should be cleaned and coated rather than left open, which is where fence painting and staining extends the life of the repair considerably.
Key Takeaways
Identify the cause first. Settling, erosion, digging, slope, frost heave, and missing tension wire each call for a different fix.
Bottom tension wire is the standard, low-cost method and is often simply missing from budget installations.
A bottom rail resists both pushing and lifting and is the strongest option short of concrete.
An L-footer apron laid flat on the ground is the most effective anti-digging method, because dogs dig at the barrier rather than backing away from it.
Standard chain link mesh openings are large enough for small pets to pass through even with no gap, so add smaller-gauge mesh along the lower section.
Loose posts cause many bottom gaps. Footings must sit below the frost line and be crowned so water sheds away from the post.
Gates need their own solution, since clearance to swing means a gap exists by design.
Frequently Asked Questions
What is the cheapest way to secure the bottom of a chain link fence?
Ground stakes or anchor pins driven through the bottom of the fabric cost the least and install quickly. They handle pushing adequately but will not stop a dog that digs, and they loosen over time in soft soil.
How do I stop my dog from digging under the fence?
An L-footer apron is the most reliable method. Wire mesh is bent outward at a right angle and laid flat on the ground inside the fence, then staked and covered. Dogs dig at the base of the barrier, hit the mesh, and give up. For a persistent digger, a concrete footer is the permanent answer.
Should I bury the fence fabric underground?
It works, but buried galvanized fabric corrodes faster than fabric above grade, particularly where road salt is present. Vinyl-coated fabric holds up better below grade. In many cases a surface apron outperforms burial for less digging and less corrosion risk.
How do I secure a fence post that has come loose?
Excavate the post and set a new footing below the frost line, crowning the concrete so water runs away from the post rather than pooling against it. Terminal and corner posts need larger footings than line posts. Packing gravel or dirt around a loose post is a temporary measure at best.
Why does the gap keep coming back after I fill it in?
Usually drainage. If water runs along the fence line, it will re-excavate any soil you add. Redirect the downspout or regrade the path first, then close the gap with a hard surface such as pavers rather than loose fill.
Can I secure the bottom of a fence myself?
Tension wire, stakes, pavers, and mesh are reasonable homeowner projects. Bottom rails, concrete footers, and resetting fence posts are better handled professionally, since footing depth determines whether the repair survives a winter.
Conclusion
Securing the bottom of a fence is straightforward once the cause is clear. Pushing calls for tension wire or a bottom rail. Digging calls for an apron or concrete. Small pets call for tighter mesh. Recurring gaps almost always trace back to drainage or a post that has moved, and neither is solved by filling the hole again.
Americana Iron Works & Fence has repaired and installed fencing across Chicago and the surrounding suburbs for over 30 years, including bottom rails, tension wire, post resetting, and full section replacement. Contact us for a free estimate and we will identify what is actually causing the gap before recommending a fix.