How a pier fails
A pier under a manufactured home is a short stack carrying a large share of the home's weight into a small patch of ground. From the bottom up: a footing pad (poured concrete, precast, or in older setups a wood pad), a column of dry stacked block or a steel jack post, a cap, and shims making tight contact with the steel I beam. Failure can start anywhere in that stack.
- The pad settles or punches into the soil. The stack stays intact but the whole thing goes down.
- The pad tips. Support is lost on one edge, the column leans, and the load concentrates further on the low corner.
- The block cracks or spalls. Common on old block that has been wet for years, or on block loaded off center.
- Shims compress, rot or fall out. Wood shims in a damp crawl area do not last forever, and a shim that drops leaves the beam floating with no contact at all.
- The pier is simply missing or was never there. Older setups and do it yourself moves frequently have too few piers for the size of the home.
Pad sizing on sandy ground
This is the part that separates a Palestine area repair from a generic one. Almost half of Anderson County's soil is in the Fuquay, Kirvin and Darco group, deep sandy and loamy, and Darco is a very deep sand. Sand does not swell and shrink the way clay does, so seasonal heave is not the driver here. What sand does is carry less load per square foot when it is loose, and move when water runs through it.
A pier pad works by spreading the load from the column over enough ground area that the pressure stays inside what the soil can carry. Cut the pad area in half and you double the pressure. On firm clay you might get away with that for a long time. On loose deep sand, the pad simply drives itself down into the material until enough sand is compacted beneath it to hold, and by then the corner of the home has dropped a visible amount. That is punching, and it is the single most common cause of a dropped pier on sandy East Texas lots.
What a contractor should be weighing when sizing pads on sand:
- The load each pier actually carries, which is not equal across the home.
- Whether the sand under the pad is loose surface material or has been compacted during site prep.
- Whether the pad is bearing on undisturbed ground or on fill that was pushed in to level the site.
- Whether the pad is set below the loose surface layer rather than on top of it.
- Whether a larger pad, a poured footing, or a different pier type is the right answer for the point load at that location.
The short version: on sand, going up a pad size is cheap compared to coming back to relevel the same corner in three years.
Scour, the other sand failure
Punching is load driven. Scour is water driven, and it is sneakier. Roof runoff with no gutters, a driveway that sheds toward the home, a slope that funnels water under the crawl area, or a leaking supply line can all move a steady stream of water through sandy soil. Sand carries away easily in moving water. A pad can end up with the soil washed out from beside it or hollowed beneath one edge while the pad top still looks perfectly normal from a distance.
The telltale signs are a small channel or fan of clean, sorted sand near a pier, a pad sitting slightly proud of the surrounding grade, or one pier that is dramatically worse than its neighbors on the same beam. Rebuilding that pier without fixing the water means rebuilding it again.
The claypan side of the county
On the western, claypan side of Anderson County, the failure mode shifts. The dense subsoil drains slowly, so water perches in the layer the pads sit in. Support softens seasonally across a broader area rather than at a single pier, and the movement pattern looks more like a whole section of the home easing down through a wet stretch and firming back up in a dry one. Fixes there lean toward drainage, footings that reach past the softened zone, and correcting how water sits around the perimeter.
What pier work usually includes
- Elevation survey to identify which piers actually lost support.
- Supporting the frame while the failed pier is removed.
- Excavating to sound bearing material rather than resetting on loose surface sand.
- Setting a correctly sized pad, level and fully bedded.
- Rebuilding the column square and plumb, with proper cap and shim contact.
- Adding piers where spacing is too wide for the home.
- Rechecking elevations across the home after the work.
Get a local contractor to look at it
Send the details through the form and a contractor who works on manufactured homes around Palestine, Elkhart, Frankston and the surrounding towns will get in touch. If you can note whether the ground under your home is sandy or heavy, that helps them come prepared.