How Deep Should Chain Link Fence Posts Be?

What Depth Do Manufacturers Give for Chain Link Posts?

Chain link terminal posts go about 30 inches (76 cm) deep in a hole about 8 inches wide, and line posts go 18 to 24 inches (46 to 61 cm) deep in a hole about 6 inches wide. These are Master Halco’s installation figures. The guide adds that local weather and soil conditions set the exact diameter and depth.

A terminal post is any post at the end of a run or at a change of direction: corner, end and gate posts. A line post is an intermediate post. The guide calls for sloping hole sides and a continuous concrete pour, finished with a trowel and sloped downward to shed water.

How Deep Should Posts Be for a 4, 5 or 6 Foot Chain Link Fence?

The depth does not change with fence height in the manufacturer’s guide, but the post length does. A terminal post stands above ground at the fabric height plus 2 inches. Add the 30 inches in the ground and you have the length to buy. The numbers below follow from that rule.

Round up to the next length your supplier stocks. Line posts are set 18 to 24 inches deep, and their height above ground follows your fence manufacturer’s sheet. Space line posts evenly at no more than 10 ft apart; the guide gives a chart that divides the run between terminal posts.

How long should chain link fence posts be?

Chain link fence posts should be as long as the height above ground plus the depth in the ground. For a 4 ft fence, a terminal post needs 50 inches above ground and 30 inches buried, so 80 inches in total. Longer posts cost more but leave you room if you decide to dig deeper for frost.

Why Do Terminal and Gate Posts Go Deeper Than Line Posts?

Terminal and gate posts go deeper because they carry the load of the whole fence. Chain link fabric is stretched tight, and the tension pulls on every end and corner post. A gate adds weight and a swinging load on the gate posts. Line posts carry only their own share.

That load is why the same guide uses a wider hole for terminal posts. Plan on more concrete for each terminal post: the installation guide estimates about two 60 lb sacks of concrete mix for each post hole. Gate posts also use more tension bands and hinges than line posts.

Do Chain Link Posts Need to Go Below the Frost Line?

In cold climates, chain link posts should reach below your frost line, and the deepest hole you need is the larger of the manufacturer’s depth and your local frost depth. No national building code sets a chain link post depth, so this is practice, and a local rule can override it.

Frost can lift a post set in concrete, and a post that rises leaves the gate out of true and the fabric slack. The manufacturer’s guide tells you to follow the local weather and soil conditions rather than a single number. Look up your frost line depth to see what your code sets, then dig the terminal posts at least that deep.

Do any local codes set a chain link post depth?

Yes, a few do. The Cook County, Illinois, Department of Building and Zoning says fence post holes must be dug 42 inches deep. That figure is deeper than the manufacturer’s 30 inches, so a Cook County fence needs 42-inch holes for every post.

The model building code does not set a post depth. Section R105.2 of the 2021 International Residential Code exempts fences up to 7 ft from a building permit, but zoning and neighborhood rules can still apply. Ask your building department and your homeowners’ association before you dig.

Is 2 Feet Deep Enough for a Chain Link Fence Post?

Two feet is enough for a chain link line post, because 24 inches is the deep end of the manufacturer’s 18 to 24 inch range. It is not enough for a terminal post, which goes about 30 inches. In a frost zone deeper than 24 inches, a line post set in concrete may need to go deeper too.

If you are using the same posts for gates or corners, dig the full 30 inches. Gate posts that sit shallow lean first and drag the gate.

How Do You Set Chain Link Posts in Concrete?

Mark and dig the terminal posts first, then set line posts between them once the corners are firm.

1. Call 811 before you dig, so buried lines are marked.
2. Check your property line. The guide recommends setting posts about 4 inches inside it, so concrete does not extend onto a neighbor’s land.
3. Mark each terminal post with a stake. Gate posts need exact spacing: a gate sold for a 36-inch opening needs 36 inches inside face to inside face.
4. Dig terminal holes about 8 inches wide and 30 inches deep, with sloping sides.
5. Mark the ground line on each post, then set it plumb at the right height. Terminal posts stand the fabric height plus 2 inches above ground.
6. Pour concrete in a continuous pour, trowel the top, and slope it away from the post.
7. Set line posts after the terminal posts cure, in 6-inch holes 18 to 24 inches deep, spaced evenly at 10 feet or less.

Why Do Chain Link Posts Heave in Winter?

Chain link posts heave in winter when water in the soil freezes into ice lenses and lifts the concrete around the post. Thaw does not bring the post back down, so it rises a little each year. A post set below the frost line sits in soil that does not freeze, so it stays put.

Frost heave explains the three conditions behind this. For other fence types and their posts, see fence post depth, and for wire and rail fences on larger land, farm fence post depth.