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GGilbert Concrete LevelingConcrete Leveling & Lifting · Gilbert, AZ
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Concrete technician assessing slab support beneath an intact concrete slab in an Arizona setting

10+ Years Experience · Insured

Concrete Void Filling in Gilbert, AZ | 10+ Years Experience

Restore support beneath settled concrete — filling the open space under slabs to re-establish bearing, whether or not the surface also needs to be raised.

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Concrete void filling is centered on restoring support loss beneath concrete slabs rather than generic lifting. Voids are unsupported spaces that form beneath concrete when soil erodes, settles, or washes away from the underside of the slab, and filling them may restore support without requiring significant slab elevation. Some projects require both support restoration and controlled lift; others primarily require stabilization. Likely contributing conditions can include erosion, water movement, poor or variable compaction, settlement, washout, or changes beneath slab edges — but not every hollow sound proves a void, and no single mechanism explains every case. Method and material choice depends on access, void characteristics, slab condition, the desired support or lift, and surrounding conditions. See our concrete leveling methods comparison and the slab lifting page for the related lifting action.

Polyurethane foam may be used for selected void-filling and stabilization projects because the expanding material flows into the open space and re-establishes bearing; cementitious materials may be considered where project conditions suit a denser grout. Void filling does not repair foundation defects, and it does not guarantee that future soil movement will stop — it addresses the support beneath the slab and the conditions that led to the void. The key distinction on this page is that forcing a lift is not always the goal: sometimes the right answer is to fill and stabilize the slab where it sits, and sometimes controlled elevation correction is appropriate alongside the filling. With 10+ years of experience and insured service, Gilbert Concrete Leveling evaluates whether your slab needs stabilization, filling, or a controlled lift before recommending a treatment.

Why Choose Gilbert Concrete Leveling for Concrete Void Filling?

Void filling is about restoring support, not just raising concrete. Our role is to determine whether the slab needs stabilization, filling, or a controlled lift — and to recommend only what the conditions support.

  • 10+ Years of Experience

    A decade of evaluating and filling voids beneath Gilbert concrete, from driveway support restoration to multi-area commercial stabilization.

  • Insured

    Gilbert Concrete Leveling is insured for the void filling and slab stabilization work we perform on your property.

  • Distinguishes Stabilization From Unnecessary Lift

    We separate a slab that needs support restored from a slab that needs to be raised, because forcing a lift when the goal is stabilization is not always appropriate.

  • Multiple Material and Method Options

    We select between expanding polyurethane foam and cementitious grout based on void characteristics, access, slab condition, and whether a lift is also needed.

  • Attention to Drainage and Support Loss

    The drainage, erosion, and soil conditions that created the void are part of the evaluation, because filling the void without addressing the cause can invite the problem to return.

  • Condition-Based Recommendations

    The treatment is chosen after the void size, slab condition, and support requirements are evaluated — not as a default answer for every hollow-sounding slab.

  • Repair-vs-Replacement Guidance

    When the concrete above the void is too deteriorated to stabilize, you get an honest recommendation for replacement instead of a treatment that will not hold.

  • Clear Scope and Estimates

    Pricing is explained by the factors that drive it — void size, material volume, access, treatment locations, and whether a lift is needed — and the scope is laid out plainly.

Our Concrete Void Filling and Slab Stabilization Services

Each application below fills voids or stabilizes a specific type of concrete where the support beneath the slab has been lost. The treatment is chosen for the void characteristics and slab condition.

Driveway concrete slab stabilization scene showing support restoration work beneath a settled driveway panel

Void Filling Beneath Driveways

Void filling beneath driveways addresses the open space that forms under settled driveway panels when soil erodes or settles away from the underside of the concrete. It applies to Gilbert driveways where the support has been lost, whether or not the surface has dropped significantly.

Material — expanding polyurethane foam or a cementitious grout — is introduced at treatment points beneath the driveway panels to fill the void and re-establish bearing. The treatment is chosen for the void size, access, slab condition, and whether a controlled lift is also needed.

The result is a driveway slab with restored support beneath it, reducing the conditions that can lead to further settlement and cracking where the underlying void has been addressed.

Visible erosion void gap beneath the edge of an exterior concrete sidewalk slab where soil has washed away

Void Filling Beneath Sidewalks and Walkways

Void filling beneath sidewalks and walkways addresses the unsupported space that forms under pedestrian panels when soil erodes or settles away from the concrete. It applies where the support beneath a sidewalk or walkway has been lost, often near slab edges and transitions.

Material is introduced beneath the affected panels to fill the void and restore bearing under the concrete, with attention to the drainage and erosion conditions that created the void. The goal may be stabilization rather than significant elevation change.

The outcome is a sidewalk or walkway with restored support beneath it, reducing the conditions that can lead to further panel movement and cracking where the underlying void has been addressed.

Polyurethane foam injection equipment being used to fill a void beneath a concrete slab in a controlled work scene

Patio and Pool Deck Void Filling

Patio and pool deck void filling addresses the open space that forms beneath exterior living slabs when soil erodes or settles away from the underside of the concrete. It applies to patios and pool decks where the support has been lost, often near edges, coping, and landscape borders.

Material is introduced beneath the settled area to fill the void and re-establish bearing, with attention to the deck drains, expansion and isolation joints, and the pool-edge relationships. The slab condition is evaluated to confirm the sections are sound enough to stabilize.

The result is a patio or pool deck slab with restored support beneath it, reducing the conditions that can lead to further settlement and cracking where the underlying void has been addressed.

Technician reviewing concrete slab elevation and support condition with measurement tools

Slab Stabilization Without Major Lifting

Slab stabilization without major lifting fills voids and restores support beneath a slab that is still near the correct elevation but has lost bearing underneath. It applies where the goal is to re-establish contact beneath the concrete rather than to raise it significantly.

Material is introduced beneath the slab to fill the void and stabilize the concrete where it sits, without forcing an unnecessary lift. This is appropriate when the support has been lost but the surface elevation remains largely acceptable.

The result is a stabilized slab with restored bearing beneath it, addressing the conditions that can lead to future settlement and cracking without the disruption of raising concrete that does not need to be raised.

Controlled polyurethane void filling and slab lifting work context on a residential concrete surface

Void Filling With Controlled Slab Lifting

Void filling with controlled slab lifting combines support restoration with elevation correction for a slab that has both lost bearing and dropped below the surrounding surface. It applies where the void beneath the concrete needs to be filled and the surface also needs to be raised.

Material is introduced at treatment points beneath the slab to fill the void and produce a controlled lift, with the elevation monitored as the material works beneath the concrete. The treatment distinguishes between filling the void and raising the slab, and manages both where appropriate.

The result is a slab with both restored support and corrected elevation, reducing the trip transition and the conditions that led to the settlement in a single treatment where the slab condition supports it.

Commercial flatwork stabilization scene showing support restoration beneath a settled concrete slab

Commercial Flatwork Stabilization

Commercial flatwork stabilization addresses voids and lost support beneath pedestrian surfaces on HOA, multifamily, retail, and office properties where the slab remains suitable for stabilization. It applies where the support beneath commercial flatwork has been lost.

Material is introduced beneath the affected slabs to fill voids and restore bearing, with attention to phasing, pedestrian access, and the drainage conditions that created the void. The treatment is chosen for the void characteristics and site access.

The outcome is stabilized commercial flatwork with restored support beneath it, reducing the conditions that can lead to further settlement and transitions on managed properties where the concrete is sound enough to stabilize.

What Creates Voids Beneath Concrete in Gilbert?

Voids beneath concrete usually have more than one contributing cause. These are the factors most commonly found beneath settled Gilbert flatwork.

Water Movement and Erosion

Water moving along joints, edges, or downspout discharge can carry soil away from beneath a slab, creating an open space where the support has been removed. Erosion is one of the most common sources of voids beneath exterior flatwork.

Variable or Settling Fill

If the fill or subgrade beneath a slab was not uniformly compacted, it can settle unevenly over time and leave an unsupported space beneath the concrete. The slab above loses bearing and can crack or drop.

Changing Soil Moisture

Gilbert soil goes through wet and dry cycles driven by monsoon moisture and irrigation. As soil moisture changes, the ground beneath a slab can shrink, shift, or settle away from the underside of the concrete, creating a void.

Washout Near Slab Edges

Slab edges are particularly vulnerable to washout because water and soil movement concentrate there. Soil can erode from beneath an edge and leave the perimeter of the slab unsupported even when the center remains intact.

Settlement Beneath Exterior Flatwork

As the soil beneath exterior flatwork settles over time, it can pull away from the bottom of the slab and create a void. The concrete above it loses support and can crack, tilt, or drop into the open space.

Signs a Concrete Slab May Have Lost Support

These are common signs that a slab may have a void beneath it. A hollow sound is one possible indicator, not a diagnosis — an on-site evaluation confirms whether support has been lost.

Visible Settlement

A slab that has dropped, tilted, or developed a new low area may have lost the support beneath it. Visible settlement is often the first sign that a void has formed underneath.

Repeated Movement at a Transition

When a transition between two slabs keeps moving or worsening over time, the lower slab may be losing support beneath it. Repeated movement at a joint can indicate an ongoing void condition.

Hollow-Sounding Area

A slab that sounds hollow when tapped may have an unsupported space beneath it, though a hollow sound alone is not a diagnosis. An evaluation confirms whether a void is actually present and whether it needs treatment.

Slab Edge Appears Unsupported

When the edge of a slab is exposed and the soil beneath it has pulled away, the perimeter may be unsupported. An edge void is often visible at the perimeter before it affects the center of the slab.

Void Becomes Visible at Perimeter

A gap beneath a slab that becomes visible at the perimeter is a clear sign that the support has been lost. Visible voids at the edge should be evaluated before the slab drops further.

Water or Erosion Evidence Near Slab

Signs of water movement, erosion, or soil washout near a slab can indicate that soil is being carried away from beneath the concrete. Drainage evidence near a slab is part of any void-filling evaluation.

Adjacent Slab Relationships Change

When the relationship between two adjoining slabs changes — one drops, tilts, or shifts relative to the other — the lower slab may have lost support beneath it. Changes at transitions are a common sign of void formation.

Our Concrete Void Filling Process

A clear, condition-first process keeps the treatment straightforward from evaluation to final review.

  1. 1

    Evaluate the Slab and Surrounding Conditions

    The slab is inspected for settlement, cracking, and overall condition, and the surrounding drainage, erosion, and soil conditions are reviewed to understand what created the void.

  2. 2

    Identify the Support Problem

    The likely void areas and loss-of-support conditions are located so the treatment targets the actual open space beneath the concrete, not just the visible symptoms on the surface.

  3. 3

    Decide Whether Stabilization, Filling, or Lift Is Needed

    Based on the void characteristics, slab condition, and elevation, the treatment is chosen — stabilization without major lifting, void filling, or void filling with a controlled lift. Replacement is recommended if the slab is too deteriorated.

  4. 4

    Perform the Selected Support Treatment

    Material — polyurethane foam or cementitious grout — is introduced at the identified treatment points to fill the void and re-establish bearing beneath the concrete, with the process monitored as the material works under the slab.

  5. 5

    Review Elevation, Support, and Next Steps

    The recovered support, any elevation correction, drainage implications, and cleanup are reviewed, and follow-up or drainage guidance is explained. No hazardous DIY drilling or injection is expected of the property owner.

How Much Does Concrete Void Filling Cost in Gilbert?

Exact price depends on the specifics of your void and slab and is set after an on-site evaluation. Detailed local dollar ranges are not published here because responsible pricing requires inspecting the project. These categories show what drives the cost of concrete void filling.

Job typeTypical rangeWhat affects price
Small localized voidProject-specific estimateDriven by the void size and depth, slab area, material volume, access, number of treatment locations, and whether stabilization only or a lift is also needed. A single small void sits at the lower end of the range.
Driveway support restorationProject-specific estimateDriven by the void volume, number of affected panels, material volume, access, slab condition and thickness, drainage and erosion context, and whether a controlled lift is also needed.
Sidewalk or walkway stabilizationProject-specific estimateDriven by the void size, number of affected panels, material volume, access, drainage context, treatment locations, and whether the walkway needs stabilization only or a lift.
Patio or pool deck stabilizationProject-specific estimateDriven by the void volume, deck area, material volume, pool-edge access, drains and joints, landscape constraints, treatment locations, and whether a lift is also needed.
Multi-area commercial stabilizationProject-specific estimateDriven by the number of affected areas, total void volume, material volume, site access, mobilization, phasing, pedestrian coordination, slab condition, and whether separate drainage or site corrections are needed.

Ready to Restore Support Beneath Your Concrete?

Get a clear estimate and honest guidance on whether your slab needs void filling, stabilization, or a controlled lift.

Call 602-905-1220Or fill out the form →

Request an Estimate

Tell us about your project. We'll follow up with clear pricing and next steps.

The customer/project address for the work.

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Consent is optional. You may request an estimate without opting in to text messages.

Does Void Filling Always Lift the Concrete?

No. Concrete void filling can be used primarily to restore support beneath a slab, while controlled elevation correction is a separate objective when the slab also needs to be raised. Some projects require both; others primarily require stabilization without significant elevation change.

Forcing a lift is not always appropriate. When the support beneath a slab has been lost but the surface is still near the correct elevation, the right treatment may be to fill the void and stabilize the concrete where it sits — raising it further could create an unacceptable transition at adjoining surfaces, coping, drains, or joints. When the slab has both lost support and dropped below the surrounding surface, void filling with a controlled lift combines both objectives in a single treatment.

The distinction matters because it changes the material, the treatment points, and the cost. Stabilization without major lifting may require less material and fewer treatment locations than a combined fill-and-lift project. Void filling does not repair foundation defects, and it does not guarantee that future soil movement will stop — it addresses the support beneath the slab and the conditions that led to the void. An on-site evaluation determines whether your slab needs stabilization, filling, or a controlled lift.

What is a void beneath a concrete slab?

A void is an unsupported open space that forms beneath a concrete slab when the soil beneath it erodes, settles, or washes away from the underside of the concrete. Once a void exists, the slab above it loses bearing and can crack, settle, or drop. Void filling addresses that lost support by introducing material into the open space to re-establish contact beneath the concrete.

What causes voids under concrete in Gilbert?

Voids under concrete in Gilbert are caused by a combination of water movement and erosion, variable or settling fill, changing soil moisture from monsoon cycles and irrigation, washout near slab edges, and settlement beneath exterior flatwork. No single mechanism explains every void, which is why the surrounding drainage and support conditions are evaluated before a treatment is recommended.

Does concrete void filling always raise the slab?

No, concrete void filling can be used primarily to restore support beneath a slab, while controlled elevation correction is a separate objective when the slab also needs to be raised. Some projects require both support restoration and lift; others primarily require stabilization without significant elevation change. Forcing a lift is not always appropriate when the goal is simply to fill the void and re-establish bearing.

Can polyurethane foam be used to fill concrete voids?

Yes, expanding polyurethane foam can be used to fill selected concrete voids because the material flows into the open space beneath the slab and expands to fill it, re-establishing support. Cementitious materials may also be considered where project conditions suit a denser grout. The material is chosen based on void characteristics, access, slab condition, and whether a lift is also needed.

Can void filling stabilize a driveway or sidewalk?

Yes, void filling can stabilize a driveway or sidewalk by filling the unsupported space beneath the concrete and restoring bearing under the slab. This is useful where the support has been lost even before the surface has dropped significantly, because it addresses the conditions that can lead to further settlement and cracking. An on-site evaluation determines whether the slab needs stabilization, filling, or a controlled lift.

How do you know whether a slab needs stabilization or lifting?

Whether a slab needs stabilization or lifting is determined by an on-site evaluation that assesses the slab condition, the void size and location, the amount of elevation loss, and the support requirements beneath the concrete. If the support has been lost but the slab is still near the correct elevation, stabilization may be the goal. If the slab has also dropped, controlled lifting may be appropriate alongside void filling.

How do I request a concrete void filling estimate in Gilbert?

You can request a concrete void filling estimate in Gilbert by calling 602-905-1220 or by filling out the estimate form on this page. Provide your name, phone number, email, project address, and a brief description of the concrete concern. A team member will follow up to schedule an on-site evaluation and determine whether void filling, stabilization, or controlled lifting is the right approach.

Request a Concrete Leveling Estimate

Talk to a Gilbert concrete leveling specialist with 10+ years of experience. Insured work, clear pricing, and a straightforward process — no pressure.

602-905-1220

Request an Estimate

Tell us about your project. We'll follow up with clear pricing and next steps.

The customer/project address for the work.

Privacy PolicyTerms & Conditions

Consent is optional. You may request an estimate without opting in to text messages.

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