# Sinking Slab vs Foundation Problem: How to Tell | New Orleans Concrete Leveling > Sinking slab vs foundation problem: the signs that point to flatwork only, the signs that need a structural engineer, and how New Orleans raised houses differ. URL: https://concretelevelingneworleans.com/guide/sinking-slab-or-foundation-problem/ Decision Guide # Sinking slab vs foundation problem: how to tell the difference Most sunken concrete around a house is flatwork, not foundation. Here's how to tell the difference before you call anyone. By New Orleans Concrete Leveling · Updated September 24, 2026 Sinking slab vs foundation problem comes down to where the movement is. It's the slab if **walls are straight, doors work and the crack stays in the slab**. It may be the foundation if you see **stair-step wall cracks, sticking doors, or cracks running up the wall** — call a structural engineer first. [New Orleans Concrete Leveling](https://concretelevelingneworleans.com/) handles slab leveling — driveways, walks, patios, garage floors and slab floors — not foundation repair. So here’s an honest way to tell which one you’re looking at. This is general guidance, not an engineering assessment. ## Signs it’s the slab only - The crack is **in the concrete slab** and doesn’t continue into the walls. - **Walls are straight** and free of new diagonal or stair-step cracks. - **Doors, windows and the garage door** open and close normally. - There’s a **gap between the slab and the wall** or porch — the slab moved, the structure didn’t. - The drop is at an **edge**: the garage door, a downspout corner, the joint with the driveway. These are leveling jobs: [garage floor](https://concretelevelingneworleans.com/garage-floor-leveling/), [driveway](https://concretelevelingneworleans.com/driveway-leveling/), [patio](https://concretelevelingneworleans.com/patio-porch-leveling/), [interior slab](https://concretelevelingneworleans.com/interior-slab-leveling/). ## Signs it may be the foundation - **Stair-step cracks** in brick or block walls, or diagonal cracks from door and window corners. - **Doors or windows sticking**, or gaps at the top of doors that change over time. - **Cracks that run from the floor up the wall**, or across the foundation itself. - **Floors sloping across the whole house**, not just one room or addition. - **Gaps at the ceiling line** or between walls and trim. If you see these, get a structural engineer’s opinion before any contractor quotes a fix. Only the slab moved? Get a free leveling estimate. If anything looks structural, the estimate will say so. [Call (504) 517-8336](tel:+15045178336) [Use the cost estimator](https://concretelevelingneworleans.com/tools/concrete-leveling-cost-estimator/) ## How New Orleans houses change the picture **Raised houses on piers or pilings.** The main floor is framing on piers, and everything around it — walks, steps, patios, carport slabs — sits on soil. When that soil settles (the [City of New Orleans](https://ready.nola.gov/hazard-mitigation/hazards/subsidence/) puts average subsidence at about 0.2 inches a year), the concrete drops away from a house that holds still. That’s a flatwork problem. Leveling the house itself is a separate trade. **Slab-on-grade homes** (common in Metairie, Kenner, Chalmette and the Westbank). The house slab and the flatwork were poured separately. A dropped driveway or patio beside a straight, trouble-free house is flatwork. Cracks through the house slab with interior symptoms are a foundation question. **Additions and converted garages.** Often poured later on newer fill. A floor sloping only in the addition is usually a slab issue in that addition — see [interior slab leveling](https://concretelevelingneworleans.com/interior-slab-leveling/). ## Bottom line **Straight walls, working doors and a crack that stays in the slab** mean flatwork — a leveling job. **Stair-step wall cracks, sticking doors and cracks up the wall** mean call a structural engineer first. For a free slab estimate, call **[(504) 517-8336](tel:+15045178336)** — free estimate within 24 hours. ## Quick answers ### Can concrete leveling fix a foundation problem? No. Leveling lifts slabs on grade — driveways, walks, patios, garage floors and some interior slabs. Foundation movement in footings, grade beams or piers needs a foundation contractor or structural engineer. ### My house is on piers. Is the sunken walk a foundation issue? Almost never. On a raised New Orleans house, the walk, steps and patio sit on soil while the house sits on piers or pilings. The flatwork settling is separate from the house structure, which is a house-leveling trade. ### Who should I call first if I'm not sure? If any foundation signs are present, a structural engineer gives an independent opinion before anyone sells you a repair. If only the flatwork has moved, a leveling estimate is the right first call. [Related service Garage Floor Leveling Raise a sinking garage or carport slab, close the step at the driveway and find out whether the cracking is structural. Mudjacking: $1,400–$3,200 · Foam: $2,880–$9,000 See how it works](https://concretelevelingneworleans.com/garage-floor-leveling/) Free, no-hassle quote [(504) 517-8336](tel:+15045178336) Free estimate within 24 hours. ## More guides - [Learn Is a sunken concrete slab dangerous?](https://concretelevelingneworleans.com/guide/is-a-sunken-slab-dangerous/) - [Local Guide Why does concrete sink in New Orleans?](https://concretelevelingneworleans.com/guide/why-new-orleans-concrete-sinks/) - [Decision Guide Can you level a cracked concrete slab?](https://concretelevelingneworleans.com/guide/can-you-level-a-cracked-slab/) - [Local Guide Louisiana concrete contractor license requirements: does a leveling job need one?](https://concretelevelingneworleans.com/guide/louisiana-contractor-license-concrete/) - [Learn Will my concrete sink again after leveling?](https://concretelevelingneworleans.com/guide/will-my-slab-sink-again/) Stop guessing. Get your slab measured. Call now for a free, no-hassle quote. Estimates within 24 hours. [Call (504) 517-8336](tel:+15045178336) [Request a free estimate](https://concretelevelingneworleans.com/contact/)