# How Should Fence Posts Be Set in Wet Clay Soil? > How fence posts are set in wet clay and silt soil around Hammond, LA: why posts move, how depth is chosen, gravel vs concrete footings and wet post holes. URL: https://palisadeshammondfence.com/guide/fence-posts-in-wet-clay-soil/ Learn What the ground under a Hammond-area fence is actually like, why posts rotate in it, how footing depth and type are chosen, and how a post hole that fills with water is handled. Last Updated: November 1, 2026 In wet ground the hole matters as much as the post. A footing that drains and sheds water outlasts a deeper one that holds it. Mon to Fri 8 to 6 · Sat and Sun 9 to 2 In wet clay or silt, fence posts need a footing that resists rotation and keeps water off the post: a hole sized for the fence height and face, crushed stone at the base so water drains, and concrete crowned above grade so rain runs away. The depth follows the fence and the soil, not a single number. [Palisades Hammond Fence](https://palisadeshammondfence.com/) installs fences in Hammond and across Tangipahoa Parish, western St. Tammany and eastern Livingston Parish, where most of the mapped ground is poorly drained and wet near the surface. This guide explains what that ground does to a post, how a [fence installation](https://palisadeshammondfence.com/fence-installation/) chooses post depth and footing type, and what happens when a hole fills with water. Key takeaways - Around Hammond the soils are mostly poorly drained silt loams, with the seasonal water table 13 to 69 cm below the surface at the points sampled (USDA NRCS). - Posts in saturated soil rotate under loads they would resist in dry soil, which is how leaning starts. - Depth is set by fence height, how solid the face is, gate loads and the soil, not by frost: Hammond averages about 31 freezing nights a year, all brief. - Crushed stone at the base drains the hole; concrete crowned above grade sheds water away from the post. - Posts set in concrete are allowed to cure before rails, panels or gates go on. ## What the ground is actually like here People call it clay, and some of it is. The USDA NRCS soil survey maps the ground around Hammond as mostly Guyton and Brimstone-Guyton silt loams, with Abita silt loam and Myatt fine sandy loam, and classes eight of nine sampled points as poorly drained ([USDA NRCS Web Soil Survey](https://websoilsurvey.nrcs.usda.gov/)). Silty clay loam shows up near Covington and Madisonville. What these soils share with clay is the part that matters for posts: fine particles, slow drainage and a weak grip when saturated. The water table is the bigger issue. Point samples show how close it comes to the surface across the area. | Area | Main drainage class at sampled points | Seasonal water table, median of points | | --- | --- | --- | | Hammond | Poorly drained (8 of 9) | 23 cm (about 9 in) | | Ponchatoula | Poorly and somewhat poorly drained | 23 cm | | Covington | Mostly poorly drained | 20 cm | | Madisonville | Very poorly drained at 4 of 9 | At the surface | | Killian | Somewhat poorly drained | 30 cm | | Loranger | Moderately well drained | 33 cm | | Folsom | Moderately well drained | 52 cm | These are point samples, not findings for any one lot. They explain why a post hole dug in a wet month around Hammond often has water at the bottom before anything goes into it. The [Covington page](https://palisadeshammondfence.com/service-areas/covington/) covers the sandier ground there. ## Why posts lean in wet soil A fence post works as a lever fixed in the ground. Wind or a gate pushes the top one way; the soil near the surface pushes back on the front of the post and the soil near the bottom pushes back on the rear. When those two zones hold, the post stays plumb. Water weakens both. Saturated fine soil carries load poorly because water in the pores takes pressure off the contact between grains. Push on a post in that state and it moves a little, leaving a small void the soil doesn’t refill. Rain then finds the void. Homeowners report fences on soft ground starting to lean during a storm’s rain, at the posts that carry the most load, such as a double gate. ### Why shallow posts are the first to go Improper post depth turns that soil weakness into instability quickly. A shallow post has a short lever below ground and depends on the top layer of soil, which is the layer that saturates first and dries last. A deeper post engages more soil over a longer lever, so each square inch has less work to do. ## How post depth is chosen There is no single right depth, and a quote that applies one number to every post on every lot is skipping steps. Depth comes from four things: - **Height.** A taller fence puts its load higher, lengthening the lever on the footing. - **Face.** A solid [privacy fence](https://palisadeshammondfence.com/privacy-fence-installation/) face catches far more wind than open pickets, chain link or aluminum. - **Gates.** [Gate](https://palisadeshammondfence.com/gate-installation/) hinge posts carry the gate’s weight as a constant sideways pull, so they get more depth and a larger footing than line posts. - **Soil and water.** Softer, wetter ground needs more depth, more footing width, or both. ### Frost is not the driver here In cold climates posts go below the frost line so freezing soil can’t lift them. NOAA’s climate normals for the Hammond station record about 31 nights a year at or below freezing, with a winter mean low near 40 F ([NOAA NCEI](https://www.ncei.noaa.gov/)). No local frost-depth design value was found, and those freezes are brief and shallow. Wind, soft soil and water set post depth around Hammond. ## Footing options compared Homeowners report conflicting advice on whether to set posts in dirt, gravel or concrete, and each answer is right somewhere. In wet ground the trade-offs look like this. | Footing | How it holds | Where it fits | What to watch | | --- | --- | --- | --- | | Tamped native soil | Friction and soil bearing only | Light, open fences in firm, drained ground | Loosens fast when saturated | | Compacted crushed stone | Interlocking stone, drains freely | Wood posts on better-drained lots; farm lines | Less grip in very soft soil; needs firm compaction | | Concrete over a stone base | Concrete spreads load; stone drains the post end | Most residential privacy and picket fences here | Finish must be crowned, not flat or cupped | | Concrete with a steel post | Rot-free post, stiff section | Wind-exposed runs, gate posts, wet lots | Coating at grade; footing still sized for soil | | Driven steel posts | Friction along the driven length | Farm and agricultural lines | Limited hold in soft, wet ground for tall faces | The concrete detail at the surface matters more than most people expect. Concrete finished flat or cupped at the grass line holds a ring of water against a wood post after every rain, which is where a post rots. Concrete brought slightly above grade and sloped away sends that water out into the yard. ## Setting posts in a wet hole When the hole fills, the method changes: 1. Bail or pump out standing water just before setting the post. 2. Place several inches of compacted crushed stone at the bottom so the post end can drain. 3. Set and brace the post plumb. 4. Place concrete from the bottom up, letting it push water ahead of it out of the hole. 5. Crown the top above grade and slope it away from the post. 6. Let the concrete cure before rails, panels or gates load the post. Homeowners report crews pouring dry mix into holes and adding no water. Some dry-set mixes are designed to draw moisture from the ground, but in a hole holding standing water, loose dry mix can separate and set weak. Ask how wet holes will be handled before work starts. ## Choosing the post itself The post matters as much as the hole. Wood posts need lumber treated for ground contact, not above-ground stock; the [post rot and termites guide](https://palisadeshammondfence.com/guide/fence-post-rot-and-termites/) explains why. Hammond’s code requires wire fences to use galvanized pipe at least 1.5 inches across, spaced no more than 7 ft apart, and requires weatherproofed wood for wood fences ([Hammond UDC 4.1.8](https://hammond.org/wp-content/uploads/2024/07/20240624_UDC.pdf)). Vinyl and aluminum systems use hollow posts that rely entirely on their footing; aluminum or steel inserts stiffen them at gates and on windy runs. On [wood fences](https://palisadeshammondfence.com/wood-fence-installation/) in the wettest spots, galvanized steel posts with a wood face remove the rot problem at grade altogether. A [wind-resistant fence](https://palisadeshammondfence.com/wind-resistant-fence/) combines these choices with closer spacing. ## Signs your posts are moving - A ring of open soil or a crack around the footing at the surface - A post that rocks when pushed at shoulder height - Water standing at the base of a post days after rain - A gate that has started to drag or miss its latch - Rails pulling away from a post at one end One moving post can often be reset or replaced; a whole run moving together points to a wider problem. The [fence post replacement](https://palisadeshammondfence.com/fence-post-replacement/) page covers the repair, and the [why fences fail guide](https://palisadeshammondfence.com/guide/why-fences-fail/) covers the other causes. Call Palisades Hammond Fence at [(985) 866-3827](tel:+19858663827) or [request an estimate](https://palisadeshammondfence.com/contact/) for a post plan matched to the ground on your lot. ## Questions about this guide ### Is gravel or concrete better for fence posts in wet ground? Each solves a different problem. Compacted crushed stone drains and lets a wood post dry, but gives less grip in soft soil. Concrete grips better and spreads the load, but can hold water against wood if it is finished flat at the grass line. In wet ground the common answer combines them: gravel under the post end and concrete crowned above grade. ### Can fence posts be set when the post holes fill with water? Yes, with care. Water is bailed or pumped out, a few inches of crushed stone go in the bottom, and concrete is placed from the bottom up so it pushes water out rather than mixing with it. Dry mix poured into standing water can wash out and set weak. In the wettest season, scheduling around rain is sometimes the better choice. ### Do steel fence posts hold better than wood in soft soil? Steel posts don't rot at the ground line, which removes the most common failure in wet ground, and galvanized pipe is stiff for its size. They still need a footing sized for the soil and the fence, because soft ground lets a steel post rotate just as it does a wood one. A wood fence face can be fastened to steel posts. ## Related service ### Fence installation → New wood, vinyl, chain link, aluminum and steel fences, laid out to the local rules and built on a post plan for wet ground and storm wind. ## More guides Learn Why Do Fence Posts Rot at Ground Level? Why decay concentrates in the few inches around grade, why treated posts still fail, how termite damage differs, how to test a post without pulling it, and what a lasting fix looks like. Learn Why Do Fences Lean, Rot and Blow Down Around Hammond? How fences are built here, the ways they fail in wet ground and storm wind, how to read the symptoms, and what a repair or a rebuild should change. Decision Guide How Do You Plan a Fence Around Hammond, LA? The order that keeps a fence project from stalling: where the line is, which rules apply, how the run and gates are laid out, what gets located before digging and what the ground asks of the posts. Learn How Long Does a Wood Fence Last Around Hammond? Why no honest figure fits every fence, which parts wear out first in this ground and climate, how sun weathers each material, and what to do to stretch the years. Learn Can You Put a Fence in a Drainage Easement? What a drainage or utility servitude on your plat means for a fence, who answers for a ditch between two lots, why a solid fence can't dam natural runoff, and how fences are planned on flood-prone ground.