How to Install a Dog Fence Extension | Add Height or Stop Digging

Two problems send people searching for a dog fence extension: a dog that clears the top, and one that tunnels under. The fix differs completely for each. Height extensions bolt onto your current fence and add mesh above it, while dig-proofing lays a wire apron flat along the ground. Installing a dog fence extension is a weekend job either way, and the steps below cover both approaches with the exact hardware and layout rules that keep the result stable.

How Do You Extend Fence Height?

You attach extension arms to the top of your existing posts or top rail, then fasten new fence mesh to those arms. Both use the same core install sequence.

• Measure and mark. Decide your finished added height before mounting anything. Run a string or chalk line across the posts so every arm sits at the same level — skipping this produces a wavy, uneven fence line.
• Mount the arms. Align each extension arm on a post or the top rail and secure it with the manufacturer’s hardware. Dog Proofer’s instructions call for (2) U-bolts of the appropriate size for chain-link posts, and outdoor wood screws or lags on other materials where possible.
• Unroll and attach the mesh. Unroll the fence material across several posts first, then go back to the start. Fasten the top of the mesh to the top of each arm with zip ties, then add 3–4 more ties down each post.
• Finish the corners. When you reach a corner or end point, add extra ties to prevent sagging and gaps. On curved systems, attach the mesh to the arms with the provided heavy-duty zip ties and trim the excess tie material.

For homeowners weighing which system fits their yard, our roundup of the best dog proofer fence extension arms compares the curved and vertical kits side by side.

How Do You Make a Fence Dig-Proof?

Rather than adding height, a dig-proof extension lays a mesh apron along the fence base so a dog can’t tunnel underneath. Dig a trench along the fence line, bend the mesh into an L-shape, and bury the horizontal portion inside the enclosure.

1. Dig a trench along the fence line, roughly 6–12 inches deep.
2. Bend the mesh into an L-shape so the vertical portion sits against the fence and the horizontal portion lies flat on the ground inside the pen.
3. Secure the vertical mesh to the fence base with hog rings or heavy-gauge wire.
4. Pin the flat portion to the ground with 12-inch galvanized ground stakes driven with a hammer.
5. Backfill and compact the soil over the trench. Skipping the compaction step leaves gaps a determined digger can exploit.

For freestanding barrier builds, Wirefence’s installation guide recommends folding down spiral connectors so no pointy wire ends are exposed — the same principle applies to the cut edges of your apron mesh. Wear gloves throughout; the galvanized wire edges are sharp.

Post Spacing and Layout Rules That Keep It Stable

A fence extension is only as stable as the posts beneath it. Skimp on corner posts or posts at grade changes and the whole run will sag or pull out of alignment. Follow these spacing rules and your extension will hold up for years.

On existing fences, verify your current posts meet the 9-foot maximum spacing before adding height — wider gaps mean the extension arms carry more load than they were designed for.

The most common mistakes come down to fasteners and tension. Using the wrong U-bolt size on chain-link posts leaves the arms loose; not compacting dig-proof backfill lets dogs nose under; and skipping the string line produces an uneven finished height. Fix each during installation and the extension works exactly as intended.

FAQs

Can I attach an extension to a wood privacy fence?

Yes. Dog Proofer’s instructions specify outdoor wood screws or lag bolts for non-chain-link materials. Pre-drill pilot holes to prevent splitting, and use galvanized hardware rated for outdoor exposure so the fasteners don’t corrode over time.

How much height can I add to an existing fence?

Most extension kits add between 2 and 3 feet. Keep the finished total under roughly 8 feet so the added leverage doesn’t stress existing posts.

Will a dig-proof apron stop every dog?

It stops the vast majority, but a determined digger can sometimes find a gap. Pin the apron flat with 12-inch galvanized stakes spaced closely, compact the backfill thoroughly, and check the perimeter seasonally for spots where soil has settled or eroded.