● Slab Foundation Repair · Phoenix Metro
Slab Foundation Repair in
Phoenix, AZ
Cracked, sunken, or uneven slab? We diagnose whether you have a slab-on-grade or post-tension foundation and stabilize it with an honest, written estimate.
Slab foundation repair addresses cracked, sunken, or uneven concrete slab-on-grade foundations — the type poured directly on Valley soil beneath many Phoenix homes. When expansive clay soil swells and shrinks through monsoon season, or a slab leak washes out the sub-grade beneath the concrete, the slab can crack, drop, or tilt out of level. Phoenix Foundation Repair Co. diagnoses the real cause first, confirms whether your home has a true slab-on-grade or a post-tension slab, and the repair work itself is fulfilled by Concrete Repairman®, a Valley contractor with 30+ years stabilizing and leveling slab foundations. Every job starts with an inspection and ends with a written estimate — never a guess.
Slab vs. Post-Tension: How to Tell What Your Phoenix Home Has
Not every concrete foundation in Phoenix is the same, and the correct repair method depends entirely on which type you have. A slab-on-grade foundation is a single concrete slab, lightly rebar-reinforced, poured directly on compacted soil — common in older Phoenix homes and many production-built tract homes. A post-tension slab uses steel cables (tendons) run through the concrete and tensioned after the pour, which is standard in most Phoenix-area homes built from the mid-1980s forward.
Why the distinction matters
Cutting, drilling, or aggressively lifting a post-tension slab without locating the tendons first can sever a cable under tension — a real safety hazard and an expensive mistake. Before any crack repair or leveling work begins, our team confirms which type of slab your home has, typically by checking the construction era, tendon end anchors, and a tendon locator when needed.
Signs Your Phoenix Slab Foundation Needs Repair
- Diagonal or stair-step slab cracks — Cracks running at an angle from a corner, or stepping through an interior floor, often signal a sunken slab section rather than normal concrete shrinkage.
- Sloping or uneven floors — A noticeable slope, dip, or soft spot in the slab usually means the soil beneath it has washed out, compacted unevenly, or shifted with the seasons.
- Doors and windows sticking — When a slab settles unevenly, the framing above it racks slightly, causing doors and windows to bind even though nothing else changed.
- Gaps between the slab and baseboards or stem walls — A widening gap where the slab meets an interior wall or exterior stem wall points to slab settlement, not just ordinary expansion and contraction.
Why Slabs Crack and Settle in Arizona
Phoenix slab foundations sit on some of the more reactive soil in the country. Expansive clay soil swells when it absorbs monsoon runoff or an irrigation overflow, then shrinks again as it dries out through the long Arizona summer — that swell-shrink cycle is a leading cause of slab cracking and uneven settlement across the Valley. A slab leak or a broken irrigation line can also wash fine soil particles out from under the slab, leaving a void the concrete eventually settles into once nothing is left to support it. Poor original sub-grade compaction, tree roots pulling moisture from beneath the perimeter, and the age of an older slab-on-grade all add to the risk. Most of what we see in Phoenix isn’t one dramatic event — it’s years of expansive soil movement finally showing up as a crack or a sunken slab.
How We Repair a Slab Foundation
Every slab repair starts with confirming what caused the movement, then matching the fix to the actual problem instead of a one-size-fits-all method.
Inspection & diagnosis
We confirm slab-on-grade vs. post-tension construction, map the crack pattern, and check for a slab leak or soil void before recommending anything.
Slab jacking / slab stabilization
For a sunken slab, we stabilize and raise the affected section back toward its original elevation using controlled void fill beneath the concrete.
Crack repair
Active cracks are sealed and structurally repaired to stop water intrusion and further movement; see our dedicated foundation crack repair page for method detail.
Concrete leveling
Where the slab has settled unevenly but the concrete itself is sound, we use concrete leveling — foam or mudjacking-style void fill — to re-level the surface.
Slab Foundation Repair Cost in Phoenix
Slab repair pricing depends on the extent of settlement, the repair method, and whether post-tension precautions are required.
The range covers everything from a single stabilized crack to slab jacking across a larger sunken section. Cost drivers include how much of the slab has settled, whether void fill or full slab jacking is needed, access to the affected area, and whether tendon locating is required on a post-tension slab. We don’t quote sight-unseen — every project gets a written estimate after a physical inspection, with the scope and price spelled out before any work starts.
Ask about your options during the inspection if the recommended repair turns out more extensive than expected.
Not Sure If It's Slab-on-Grade or Post-Tension?
Book a slab inspection and we’ll identify your foundation type and provide a written estimate before any work begins.
Why Phoenix Homeowners Choose Us
- 5.0★ across 269 Google reviews — Concrete Repairman®’s track record with Phoenix homeowners speaks for itself.
- 30+ years of Valley slab experience — James Belville and the Concrete Repairman® team have stabilized and releveled slab foundations across metro Phoenix for decades.
- ICRI and ACI-aligned methods — repairs follow Concrete Repair Institute and American Concrete Institute practices, not shortcuts.
- Honest slab-vs-post-tension diagnosis — we identify your actual foundation type before recommending a fix, so you’re never paying for the wrong method.
When It's Really a Post-Tension Slab
If your home was built from the mid-1980s forward, there’s a good chance you have a post-tension slab, not a plain slab-on-grade. Post-tension slabs need a different, more careful repair approach — cutting or drilling into a tensioned cable can be dangerous and expensive to fix. If our inspection finds tendons in your slab, we shift to post-tension-safe repair methods rather than treating it like a standard slab-on-grade.
DIY vs. Professional Slab Repair
A small hairline crack sealed with a store-bought epoxy kit can buy time, but it does nothing for a sunken slab or an active void underneath the concrete. DIY leveling compounds sit on top of the problem instead of correcting the soil support beneath it, and can mask a crack that’s still actively moving. Professional slab stabilization addresses the void or soil condition causing the movement, not just the symptom on the surface — which is why homeowners who try a DIY fix first often end up calling for a proper inspection anyway once the crack returns.
Recent Slab Foundation Projects
Sunken slab stabilization and void fill
Diagonal slab crack repair and re-level
Post-tension-safe slab inspection and stabilization
Frequently Asked Questions
Check your home’s construction date first — most Phoenix homes built from the mid-1980s forward use post-tension slabs with internal steel cables, while many older homes have a plain slab-on-grade. The only certain way to know is a physical inspection, since tendon anchors aren’t always visible from the surface.
Yes. Most sunken or uneven slabs can be re-leveled using void fill and concrete leveling methods rather than demolition and replacement, as long as the slab itself is structurally sound and the movement is caused by a soil void or settlement rather than a failed slab.
Foundation repair in the Phoenix area typically runs $2,200 to $8,100, with a national average around $5,200, depending on the extent of settlement and the repair method used. We provide a written estimate after inspecting the specific damage.
The best method depends on the slab and the cause of settlement — foam-based void fill is common for lighter sections and works quickly, while slab jacking-style stabilization handles more significant sunken areas. We recommend the method during inspection rather than defaulting to one approach for every job.
Repairing the crack itself only helps if the underlying cause — usually a soil void, expansive clay movement, or a slab leak — is addressed at the same time. That’s why we diagnose the cause before repairing the crack, not after.
No. Most slab stabilization, crack repair, and leveling work is done from small access points and doesn’t require homeowners to vacate the property during the project.
● Related Services
Other Foundation Repairs We Handle
Re-level an uneven slab or walkway with foam or mudjacking-style void fill.
Safe repair for tensioned-cable slabs common in newer Phoenix homes.
Structural repair for active or widening cracks in your slab or stem wall.
● Where We Work
Serving The Phoenix Metro
Get a Written Estimate for Your Slab
Book a slab inspection with Phoenix Foundation Repair Co., fulfilled by Concrete Repairman®, and get an honest written estimate before any work begins.