Foxes and coyotes can dig under a chicken run wall in under 20 minutes. The defense: a buried apron skirt — 12 inches of hardware cloth bent outward and buried 4 inches deep around the entire run perimeter. Predators dig down at the wall, hit the apron, and give up. This guide covers the apron design that actually works, the alternatives (dug-in trenches, concrete footings), and the install pattern that takes 4–6 hours for a typical 8-bird run.

The buried apron is one piece of the layered predator defense — for the full system, see Predator-Proof Chicken Coop Defense Guide.

Why Underground Barriers Are Mandatory

Foxes are evolved to dig under fences. So are coyotes, raccoons (occasionally), badgers, skunks, and rats. A coop with hardware cloth on the walls and roof but no underground barrier is breached at the ground line, every time.

The numbers from extension-service field tests:

  • Foxes: dig under a vertical fence in 15–25 minutes.
  • Coyotes: 20–35 minutes.
  • Raccoons: usually do not dig but will if other paths fail; 30–60 minutes.
  • Skunks: 10–20 minutes for partial entry (skunks rarely take birds; they take eggs).
  • Rats: tunnel continuously over weeks; eventually find a path.

An apron skirt converts "dig under in 20 minutes" to "cannot dig under at all." The mechanism: when the predator digs at the wall and hits the horizontal mesh, the predator instinct is "wrong direction" rather than "dig deeper" — they do not understand to back up and start a new tunnel further out.

Hardware cloth bent at a sharp 90 degree angle on a workbench using a 2x4 board

The Apron Design That Works

The standard buried apron design:

  • Material: 1/2" hardware cloth (or 1" welded wire if cost is critical), 19-gauge minimum, galvanized.
  • Width: 12 inches, bent outward (away from the run) at a 90° angle.
  • Burial depth: 4 inches. Deeper is unnecessary; shallower allows surface erosion to expose the apron.
  • Attachment to run wall: overlap 2" with the run-wall hardware cloth and screw through with washers every 4 inches.

The 12" outward dimension is the key spec. Predators starting their dig at the wall hit the apron after 1–2 inches of digging; they then have to dig 12 inches outward before they could clear the apron — and the deeper they dig, the further they would need to extend the trench. Almost no predator pushes through.

Extending the apron beyond 12" (say, 18" or 24") provides marginal additional defense but is not necessary. 12" is the cost-effective sweet spot.

Person digging a 4-inch trench around a chicken run perimeter with a flat shovel for buried apron installation

Step-by-Step Install

For an 8'×8' run perimeter (32 linear feet of apron):

  1. Buy materials: 32 linear feet × 12" wide = 32 sq ft of hardware cloth ($35–$50). 1 lb of fender washers + 1.5" deck screws ($15). Optional: stakes or landscape pins to hold the apron flat ($10).
  2. Trench around the run. Dig a 4"-deep trench 12" out from the run wall, all the way around. Use a flat shovel; a typical 32' trench takes 2–3 hours of work. Save the dirt — you will use it for backfill.
  3. Cut the apron strip. Use tin snips to cut hardware cloth into 12"-wide × 32'-long strips. Most rolls are 36" wide, so one cut per side gives you three 12" strips per roll.
  4. Bend the apron. Bend each strip 90° along the long axis. The bend should be sharp, not gradual — a 2×4 across a workbench helps make crisp bends.
  5. Position and attach. Lay the apron in the trench with the vertical edge against the run wall. Screw the vertical edge to the run-wall hardware cloth using fender washers, every 4 inches. The horizontal edge sits flat in the trench bottom.
  6. Stake the apron flat. Use landscape pins or homemade staples (16-gauge wire bent into U-shapes) every 24 inches along the buried edge. This keeps the apron flat against the soil while you backfill.
  7. Backfill with dirt. Cover the trench with the dirt you removed. Tamp lightly. Add 1" of soil over the top so grass can re-grow.
  8. Test. Pull on the apron edge with two hands — it should not move. If it pulls up, add more screws or stakes.

Total install time: 4–6 hours for an 8'×8' run. Single biggest time component is digging the trench; rented power trenchers cut this to under 1 hour but cost $50–$80/day.

Finished installation of a buried apron around a chicken run with backfilled trench and emerging grass

Alternatives to Buried Aprons

If digging is impractical (clay soil, rock, tree roots), three alternatives provide partial protection:

Surface apron (no burial). Lay the 12" apron flat on the ground extending outward from the run wall, weight it with rocks or concrete pavers. Less effective than buried — wind, snow, or grass growth lifts it — but stops 60–70% of digging attempts. Best for rented properties where digging is not allowed.

Concrete footing. Pour a concrete footing 6" deep × 6" wide all around the run perimeter, with the run wall built on top. Eliminates digging entirely but locks the run in place permanently. Cost: $2–$4 per linear foot in materials, plus labor.

Gravel-filled trench. Dig a 6"-deep × 6"-wide trench around the run perimeter and fill with crushed stone (3/4" minus). Predators find the gravel uncomfortable to dig through and often abort. Less reliable than apron skirts but easier to install in rocky soil.

Combination: for the highest threat level, combine buried apron skirt + concrete footing. Foxes and coyotes give up at the apron; even if they dug to the apron edge (12" out), the concrete blocks further progress.

Apron Maintenance

Buried aprons fail through ground settling, not through predator force. The maintenance:

Spring inspection. Walk the perimeter looking for spots where the apron mesh has become visible above the soil line. Frost heave pushes aprons up over winter. Stomp the apron back down or add 1–2 inches of soil over the exposed area.

After heavy rain. Erosion can expose the apron edge. Same fix: stomp down and add soil.

Annual probe. Once per year, push a long screwdriver into the soil at the run wall — verify the apron is still 4" deep. If you do not hit metal at 4", the apron has shifted and needs re-burying.

Predator activity check. If you find fresh dig marks at the run wall, walk the perimeter looking for an exposed apron edge or a section where the apron is missing entirely. The dig marks tell you exactly where the predator targeted.

Frequently Asked Questions

How deep should an underground predator barrier be?

4 inches deep is the standard for buried aprons. Deeper is unnecessary; shallower allows surface erosion to expose the apron. The width matters more than depth — 12 inches outward bend is the spec that stops fox and coyote digging.

Will foxes dig under a chicken coop?

Yes — foxes dig under a vertical fence in 15-25 minutes. The defense is a buried apron skirt: 12 inches of hardware cloth bent outward at 90 degrees and buried 4 inches deep around the run perimeter. Foxes hit the horizontal apron and give up.

What is a chicken coop apron?

An apron is hardware cloth bent outward at the base of a run wall and buried just under the soil surface. It extends 12 inches out from the wall, buried 4 inches deep. Predators digging at the wall hit the apron and cannot tunnel under.

Can I use chicken wire for an underground barrier?

No — chicken wire degrades within 2-3 years underground and is too thin to resist persistent digging. Use 1/2-inch hardware cloth in 19-gauge or thicker, galvanized for outdoor use. Cost is about $1 per square foot.

How much does a buried predator apron cost?

For a typical 8×8 ft run with 32 linear feet of apron, total materials cost $50-75: 32 sq ft hardware cloth ($35-50), washers and deck screws ($15), and optional landscape stakes ($10). Install time is 4-6 hours.

Do I need an apron if my coop floor is concrete?

Probably not for the coop itself, but yes for the attached run unless the run also has a concrete floor. Most predator breaches happen at the run perimeter, not the coop walls. The apron should run around the entire ground-level perimeter where predators could dig.