Floodwater rarely cracks a slab directly. The usual damage comes afterward: the fill and clay under the house stay saturated for days, then dry and consolidate unevenly, so one side of the slab drops. Watch for new drywall cracks at door corners, doors that start binding and gaps at windows — often months or years after the rebuild.
Foundation Repair Baton Rouge still measures homes in Denham Springs, Central, Walker and Gonzales that are showing the effects of August 2016, when 20+ inches of rain fell in five days, the Amite crested nearly five feet above its 1983 record, and about 75% of Livingston Parish homes took water.
What happens under a flooded house
- Slab homes: Water saturates the fill pad and clay beneath. As the ground dries, it consolidates — more where the fill is deepest or poorly compacted. The slab usually survives; the ground under it changes shape.
- Raised homes: Crawl spaces stay wet for days. Sills and beams soak, pier footings soften, and rot and termite activity accelerate in the months that follow.
- Scour: Fast-moving water can wash soil from around and under foundations — less common in our flat terrain but possible near bayous and ditches.
Signs to watch for after the rebuild
- New diagonal drywall cracks at door and window corners.
- Doors that fit at move-in and now bind or won’t latch.
- Gaps opening between brick and window frames or trim.
- Tile cracking in a line.
- In raised homes: floors sloping toward one wall, soft spots near exterior walls.
What insurance does and doesn’t cover
NFIP flood policies cover direct physical flood damage but exclude earth movement — including settlement — even when a flood caused it. Homeowners policies exclude flood entirely. So post-flood settlement is usually paid out of pocket. Substantially damaged, insured homes can receive up to $30,000 in Increased Cost of Compliance toward elevation. See does flood insurance cover foundation damage.
Repair in place, or raise?
If the house has flooded and sits below current base flood elevation, repairing the foundation in place leaves it exposed to the next flood. House raising costs more but addresses both. If the home is at or above flood elevation and only settlement is the issue, slab foundation repair or pier and beam repair is the practical fix — along with drainage.
Bottom line
After a flood, watch for settlement signs over the following years, not just the following weeks. For a laser survey and an honest repair-or-raise comparison, call Foundation Repair Baton Rouge.