Fencing: The Survey Line, the Exemption, and the Frost Line

What a fence in trouble looks like

Fence failures are nearly all post failures, and the pattern says whether it is the depth, the soil, the water or the wood.

• Posts leaning in the same direction along a run — the fence is acting as a sail and the posts are rotating in the ground. Either the embedment is shallow for the height, or the soil is too soft to develop resistance.
• One post leaning and its neighbours sound — a local problem: a shallow hole, a hole dug in fill, or water concentrating at that point.
• Posts that lift in winter and partly settle in spring — frost heave. The post bottom is above the frost line and the freezing soil is pushing it up.
• Rot at the soil line with sound wood above and below — the classic decay zone, where moisture and oxygen are both available. It is where wood posts almost always fail, not at the bottom.
• A concrete collar around the post with the post loose inside it — concrete poured around a post in a way that traps water against it. The collar survives and the post does not.
• Rails pulling away from posts, gates dropping and catching — movement in the posts showing up at the connections. Adjusting the gate treats the symptom.
• A gate that has always sagged — the gate post is undersized or under-braced for the leaf, or there is no diagonal bracing in the gate itself. This one is often a build defect from day one.
• A fence that runs at a visible angle to the boundary — someone built to a hedge, a tree line or a previous fence rather than to a survey.

Four fences with four different rulebooks

The four common fence types get discussed as if the only difference were the material. The rules governing them are not the same, and one of them is life-safety legislation.

What a contractor should establish before quoting a fence

A fence quoted from a linear footage and a style catalogue has not looked at the two things that decide whether it stands up and whether it stays.

• Where the property line actually is, and what evidence establishes it. A neighbour’s hedge, an old fence and "it has always been there" are not evidence.
• Whether the fence sits on the line, inside it, or straddles it — and what has been agreed with the neighbour in each case.
• The local frost line depth, which the building department publishes for your county, and which sets the minimum post embedment.
• The soil. A parcel-level lookup of the mapped soil, its drainage class, its hydrologic soil group and its shrink-swell potential — free, and soft, wet or high-shrink-swell ground changes how a post has to be set.
• Height limits by yard — front, side and rear frequently differ — and any corner-lot sightline triangle.
• Easements. A utility or drainage easement crossing the fence line can mean a fence there is removable at the utility’s convenience and at your cost.
• Homeowners association covenants on height, material, colour and which side faces the street. These bind whether or not a permit is needed.
• The grade along the run, and whether the fence steps down the slope or is racked to follow it. This changes both the appearance and the panel count.
• Utility locates. In the United States, calling 811 before digging is free and in most states it is required. A fence line is dozens of holes at post depth.
• Access for the equipment and the material, and whether a post-hole auger can reach the run at all.

What the work involves

Nine steps, and the fence is decided in the first three. Once the posts are in, everything afterwards is carpentry.

1. 01

   Establishing the line

   Locating the boundary from a survey, corner pins or a new survey where none is reliable. This is the step to pay for rather than the step to skip, because it is the only one whose failure mode is moving the entire fence.

2. 02

   Checking the rules

   Height by yard, setback, corner sightlines, easements and covenants, plus whether a permit is needed at all. Model text exempts “Fences, other than swimming pool barriers, not over 7 feet (2134 mm) high.” — but that is model text and your jurisdiction’s adoption binds, and zoning is a separate question from the building permit.

3. 03

   Finding the frost line and setting the post depth

   The frost line itself is not in the model code. It is set locally in Table R301.2 by the adopting jurisdiction, and it is the number your building department publishes for your county. It ranges from nothing in the warm south to several feet in the north, and it is the single figure that decides how deep a post or a footing has to go. A post set above it in a cold climate will be pushed up by freezing soil, and no amount of concrete around the top of it prevents that.

4. 04

   Locates and layout

   Calling 811, then stringing the line, marking every post position and working out the spacing so the run ends on a full panel rather than a sliver.

5. 05

   Digging the post holes

   Holes to the design depth and diameter, straight-sided, and cleaned out at the bottom. The model minimum in IRC R403.1.4, minimum depth is 12 inches below the undisturbed ground surface, and the frost provisions apply on top of that where they apply.

6. 06

   Setting the posts

   Posts set plumb, to the line, and to depth, with the setting method specified — concrete, compacted aggregate, or a manufacturer’s system, each of which handles water differently. As a state adoption of the frost section records: “Footings shall not bear on frozen soil unless the frozen condition is permanent.”

7. 07

   Rails, panels or pickets

   Framing between the posts and cladding it, following either a stepped or a racked line down any slope. This is the visible part and it is the part that can be corrected later.

8. 08

   Gates and hardware

   Gate posts sized and set for the leaf they carry, with diagonal bracing in the gate, and hinges and latch rated for the weight. A gate is where a fence is judged, because it is the only part anyone touches.

9. 09

   Finishing and clearing

   Any stain, seal or treatment, cut ends treated where the material requires it, spoil from the holes removed, and the line checked for straightness and consistent height before anyone signs anything off.

The two model figures, and what each one does not tell you

Model text, read as Texas Windstorm Insurance Association Building Code, 2024, section 105.2 for the exemption and as as reproduced in the Indiana Administrative Code, 675 IAC 14-4.4-43 for the frost section. Neither is your law. Both describe the shape of the rule you will be held to.

What belongs in the written scope for a fence

The part of a fence you buy and cannot inspect is underground and about three feet long. Once the posts are set and backfilled, nobody will ever see the depth, the diameter or the setting method again, and those three decide whether the fence is upright in ten years. Get them on paper.

• Post depth, stated in inches, and the local frost line it is based on. If the depth is not tied to a frost figure, ask which one was used.
• Hole diameter, and how the hole is cleaned out at the bottom.
• The setting method: concrete, compacted aggregate, or a proprietary system — and how water is kept from being trapped against the post.
• Post material, size and spacing, and the size of the gate posts specifically, which should differ from the line posts.
• How the line is established: from a survey, from corner pins, or from a new survey, and who is responsible if it turns out to be wrong.
• Where the fence sits relative to the line — on it, inside it, or straddling it — stated explicitly rather than assumed.
• Height, measured from where, and how it is maintained across a slope: stepped or racked.
• Whether a permit is required, who pulls it, and what that conclusion is based on. Separately: whether the height complies with zoning, which is a different office.
• Which side faces the street or the neighbour, since covenants and some ordinances specify this.
• Gate specification: bracing, hinges, latch, and how the gate is hung and adjusted.
• What happens to the old fence, if there is one, and to the spoil from the post holes.
• Who calls 811, and when.

A fence quote that names a style, a length and a price has priced the visible half. The depth, the diameter and the setting method are the half that fails, and they cost almost nothing to write down beforehand. The general version of the buried-work argument is on the base specification.

What moves the price

Fences are priced per linear foot, which conceals the three things that actually move the number: how deep the posts go, how hard the ground is to dig, and how many corners, gates and grade changes there are.

HyreYard publishes no average price for this work and holds no dataset of landscaping invoices. Access, soil, grade, regional labour and material availability move the number far enough that a single figure would mislead more than it helped.

What to ask before you sign

• How are you establishing the property line — from a survey, from corner pins, or from something else?
• Is the fence on the line, inside it, or straddling it, and is that written into the scope?
• What is the frost line depth here, and how deep are the posts going as a result?
• What diameter are the holes, and how are they cleaned out at the bottom?
• How are the posts set — concrete, compacted aggregate, or a proprietary system — and how does water get away from the post rather than sitting against it?
• Are the gate posts larger than the line posts, and how is the gate braced?
• Does this fence need a permit here, and what is that based on? The model exemption covers “Fences, other than swimming pool barriers, not over 7 feet (2134 mm) high.” but a permit exemption is not a zoning approval.
• What is the height limit in this yard under the local ordinance, and does a corner sightline rule apply?
• Are there easements along this line, and what happens to the fence if a utility needs access?
• Which side faces the street, and does any covenant here specify that?
• What happens to the existing fence and to the spoil from the post holes, and is that in this price?

The full ten-point checklist is on choosing a landscaping company, and the lines a comparable bid contains are on reading a landscaping estimate.

What to have ready

• Find your survey, your plat or your title documents and look for the boundary and any easements before you call anyone.
• Walk the line looking for corner pins. If you cannot find them and no reliable survey exists, price a survey as part of the project rather than as an extra.
• Talk to the neighbour before the quote, not after the posts are in. A fence on or near a shared line is a conversation that is far easier to have in advance.
• Call the building department and the zoning office and ask two separate questions: is a permit needed, and what is the height limit in this yard.
• Ask the building department for the published frost depth for your county. It is the number that decides the posts.
• Measure the run and count the corners, gates and grade changes. These are the lines that move a per-foot price.
• Look your address up on the USDA Web Soil Survey and note the drainage class, because soft or wet ground changes how a post is set.
• Check homeowners association covenants for height, material, colour and orientation rules.

Where this goes wrong

Common questions

Do I need a permit to build a fence?

The model administrative exemption covers “Fences, other than swimming pool barriers, not over 7 feet (2134 mm) high.” — so under 7 feet, and not a pool barrier, a building permit is frequently not required. But that is model text reproduced in a state-adopted code, adopting jurisdictions amend these lists routinely, and the building permit is only half the question. Zoning is the other half, it is usually a different office, and it commonly sets lower height limits in front yards, sightline rules on corner lots and setback requirements. The efficient approach is two phone calls: one to the building department about the permit, one to zoning about the height and placement where you intend to build.

How deep should fence posts go?

Deep enough to reach below the local frost line and to develop enough embedment for the height of the fence, and the first of those is a published local number. The frost line itself is not in the model code. It is set locally in Table R301.2 by the adopting jurisdiction, and it is the number your building department publishes for your county. It ranges from nothing in the warm south to several feet in the north, and it is the single figure that decides how deep a post or a footing has to go. The model code also records a minimum depth for exterior footings: IRC R403.1.4, minimum depth is recorded as requiring footings placed not less than 12 inches below the undisturbed ground surface, with the frost provisions applying on top of that. We did not read ICC’s own library for that figure and do not present it as a verbatim quotation. Ask your building department for the frost depth for your county and ask the contractor to state the post depth in the scope against it.

Whose fence is it, and who pays?

That depends on where the fence sits and on local law, and it is genuinely one of the most litigated questions in residential property. A fence built entirely inside your line on your land is generally yours to maintain and yours to remove. A fence straddling the boundary is frequently shared in some form, with the specifics set by state law and sometimes by a written agreement, and shared ownership brings shared maintenance obligations that outlast both current owners. We are not going to give you a rule, because there is not one national rule. What we will say is that the time to establish it is before the posts go in, in writing, with the neighbour, and if the sums involved are significant, with someone qualified to advise on property law where you live.

Does the good side have to face the neighbour?

Often, and it is set locally rather than by the building code. Some municipal ordinances require the finished side to face outward, many homeowners association covenants do, and in plenty of places it is purely convention. It is worth resolving before the fence is built for a practical reason as well as a legal one: reversing the orientation of a built fence means taking the cladding off and refixing it, which is most of the labour of the original job. Ask the contractor to state which way the fence faces in the written scope.

Why is my fence leaning?

Nearly always the posts rather than the fence. If a whole run leans consistently in one direction, the posts are rotating in the ground — either the embedment is shallow for the height of the fence, which acts as a sail, or the soil is too soft to develop the resistance the design assumed. If one post leans and its neighbours are sound, that hole was shallow, was dug in fill, or collects water. If posts rise in winter and partly settle in spring, that is frost heave and the post bottoms are above the frost line. Straightening and re-setting the affected posts to the correct depth addresses it; propping, bracing or re-nailing the rails does not.

Should posts be set in concrete?

It is one method among several rather than an automatic answer, and the important variable is what happens to water. Concrete gives good resistance to rotation, but poured badly it forms a bowl that holds water against a wood post at exactly the depth where wood decays. Compacted aggregate is used successfully in many soils, drains freely and lets a post be reset more easily later. Proprietary systems exist for specific products. What matters in the quote is that the method is named, that the depth reaches the frost line, and that the detail at the top keeps water moving away from the post rather than into the hole. Ask for all three rather than for concrete specifically.

Is a fence around my pool the same as a privacy fence?

Not necessarily, and this is the one on this page with the most serious consequences of getting wrong. The model permit exemption carves pool barriers out explicitly: it covers “Fences, other than swimming pool barriers, not over 7 feet (2134 mm) high.” Pool barrier requirements are life-safety provisions with their own specifications governing height, the gap under the barrier, gaps between members, climbability, and gate hardware that self-closes and self-latches out of a child’s reach. A privacy fence can satisfy a height ordinance and fail every one of those. If there is a pool, treat the barrier as a separate specification with its own rules, get it checked against the actual local requirements, and do not let it be quoted as a length of fence.

Do I need a survey?

If the line is not established by reliable, findable evidence, yes, and it is a smaller cost than every outcome it prevents. A survey is worth paying for when you cannot locate the corner pins, when the existing fence or hedge is what everyone has been treating as the boundary, when the neighbour disagrees with your understanding, or when the fence will sit close enough to the line that a small error matters. It is also worth it when the deed description is old or ambiguous. The reason this matters more for fencing than for almost any other landscape work is permanence and visibility: a fence is a physical assertion about where a boundary is, and once it is up, it is what everyone relies on until someone proves otherwise.

Sources

• Work Exempt from Permit — Texas Windstorm Insurance Association Building Code, 2024, section 105.2, Model administrative provisions as reproduced in a state-adopted building code. Checked September 5, 2026.
• IRC R403.1.4.1, frost protection — as reproduced in the Indiana Administrative Code, 675 IAC 14-4.4-43, International Code Council, International Residential Code (model document). Checked September 5, 2026.
• Web Soil Survey, USDA Natural Resources Conservation Service. Checked September 5, 2026.