A gloved hand holding an injection port over a small drilled hole in a concrete slab, with concrete dust beside it

Void Filling Experts in Hollywood Florida: Concrete Void Fill and Soil Stabilization Under Slab

Affordable Void Filling and concrete void fill in Hollywood, FL and Broward County

When sand has washed out from under your concrete, Hollywood Concrete Leveling & Repair fills the empty space in Hollywood, FL and Broward County. We handle void filling under concrete, soil stabilization under slabs and seawall void filling for homeowners, HOAs and property managers. Foam goes in through small holes, expands into the pockets and locks the soil in place. The slab keeps its support before it drops, and a slab that has dropped rises back into place.

Why homeowners choose us:

  • Free written estimates for every leveling job
  • Small injection holes patched and cleaned up after every lift
  • Water-resistant foam that does not wash out
  • Warrantied work every lift backed by a written warranty
  • Licensed and insured certificate on request

Our crew has 20+ years of experience lifting slabs in South Florida and 1,100+ slabs behind it. A void is invisible from above, so every estimate sounds the slab and probes the gap before it names a price. You get a free written estimate and a written warranty on the work. Most jobs take 2 to 6 hours.

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What Void Filling Involves in Hollywood, FL

The cause of a sunken slab is empty space in the soil, and this service treats that space directly. Your estimate can include any of these services, and each one is priced on its own line so the scope is clear:

  • Concrete void fill injects polyurethane foam into the pockets under a slab, which stops the slab from flexing over empty space.
  • Soil stabilization under slab compacts loose sand with expanding foam, so the base carries weight again.
  • Fill void under slab edges packs the washout along a driveway, patio or pool deck edge where rain gets in first.
  • Seawall void filling fills the hollow that opens behind a seawall cap when backfill escapes through the wall.
  • Combined lifting raises a slab that has already dropped, while the same pass fills the space under it.
  • Hole patching fills each injection hole with sanded concrete, so the surface is finished when the crew leaves.

When You Need Void Filling in Hollywood

A void shows up as a sound or a gap long before it shows up as a drop. Filling the space while the slab is still level costs less than lifting it later, so a hollow sound is worth a call.

Signs You Have a Void Under Your Concrete

  • A hollow, drumming sound underfoot tells you the slab is resting on air, and it will crack under the next heavy load.
  • A gap along the edge of a slab shows where soil has washed out, and each rain carries out more.
  • Soil or sand on the pavement after a storm is the sand that came out from under the slab, which means the void is growing.
  • A slab that bounces or rocks has lost its support in one spot, so the stress is landing on the cracks.
  • A seawall cap with a dip or a hollow behind it points to backfill that escaped, which leaves the yard beside it ready to sink.

Why Void Filling Is Harder in Hollywood

Voids form fast where sand meets moving water, and Hollywood supplies both. The local conditions below explain why a void here grows faster than the same void in drier ground.

Fine sand that follows the water

The NRCS soil map for the Hollywood area lists Hallandale, Margate and Basinger fine sand, and sand fill compacts poorly. Fine grains travel with any water that moves through them. A leak at a joint or an edge becomes a channel, and the channel turns into a pocket under the slab within a few seasons. Once the pocket forms, the slab flexes over it, and every flex widens the cracks that let in more water.

A water table that reaches the surface

In the wettest months the water table in Margate and Basinger fine sand sits at 0 inches, and in Hallandale fine sand about 3 inches down. Groundwater that rises and falls under a slab pulls sand with it each time. Limestone sits about 12 inches down in Hallandale fine sand, so the sand layer is thin, and a modest loss of sand leaves a large gap. Soil stabilization under a slab therefore starts with sizing the gap, because the visible crack tells you little about the pocket below.

Seawall concrete repair and washed-out backfill

Hollywood gets about 56 inches of rain a year, with nearly 70% of it between May 15 and October 15. Rain that soaks the yard behind a seawall drains toward the wall. The water leaves through joints and weep holes in the wall, and it takes fill with it. Seawall repair for this problem fills the hollow behind the cap, before the yard sinks or the cap cracks.

How Much Does Void Filling Cost in Hollywood, FL?

The price follows the slab above the void, because the foam goes in through the same holes. The size of the void and the surface it sits under move the price.

JobTypical priceKey variables
Driveway void and lift, foam$750 to $5,670number of slabs, depth of settling
Pool deck void and lift, foam$750 to $5,940larger voids, size, access around the pool
Patio void and lift, foam$750 to $4,725size, depth of the void, access
Sidewalk void and lift, foam$750 to $3,240length of the run, number of slabs
Stone slurry grout, most residential jobs$750 to $1,500void depth, access to the slab

Foam costs around 20 to 50 percent more than mudjacking or stone slurry grout, and it stays put because it is water-resistant. Filling the voids under a driveway and a pool deck in one visit saves a second trip. The same goes for a sidewalk that runs beside them.

Our Void Filling Process in Hollywood, FL

Four steps take a void from found to filled, and the estimate lists each one before work begins. A single slab is a morning job, and a seawall run or a large pool deck can take a full day.

1. Free Estimate and Sounding

You call and describe the sound or the gap, and we set up a visit. The estimator taps the slab to find hollow spots and probes the edge for the depth of the gap. You get a free written estimate with each void priced on its own line, so the scope is on paper before anyone drills. Nothing on the estimate changes unless you approve the change first.

2. Mapping the Voids

The crew marks the holes about five feet apart over the hollow areas, with more points along the edges where the washout starts. On a seawall job, the marks run along the cap behind the wall. A slab broken into small pieces is assessed case by case, and the visit says whether filling or replacing makes more sense.

3. Injecting the Foam

The crew drills penny-size holes and sets a port in each one. Liquid polyurethane foam goes in under pressure and expands through the pockets, and gauges show when the soil is compacted. Where the slab has also dropped, a slow second pass lifts it toward its original height. The foam cures in as little as 30 minutes to an hour.

4. Patching and Final Sounding

Each hole is filled with sanded concrete, and the crew taps the slab again to check that the hollow sound is gone. You can walk on the slab in 15 to 30 minutes. Heavy loads stay off for about 48 hours. Your written warranty goes into the paperwork with the final price, so the work is covered in writing.

Void Filling FAQs: Hollywood, FL

How much does void filling under concrete cost in Hollywood?

Void filling is priced with the slab above it, and foam leveling runs from $750 to $6,075 depending on the surface. The size of the void and the surface it sits under move the price. A free written estimate lists every void before any work starts.

What causes a void under a concrete slab?

Water carries sand out from under the slab through joints, cracks and edges. Hollywood sits on fine sand over limestone with a water table that reaches the surface in wet months, so voids form quickly.

Can you fill a void without lifting the slab?

Yes, if the slab is still level, the foam fills the void and compacts the soil without raising the concrete. That is the cheapest time to treat it, since the slab has not cracked yet.

Is seawall void filling the same as seawall repair?

Seawall void filling fills the hollow behind the wall, which is one part of seawall repair. A wall that has failed or tilted needs a different fix, and the visit tells you which one you have.

How long does void filling take?

Filling a cavity typically takes 2 to 6 hours, and a large cavity under a wide slab can need a full day or more.

Will the voids come back?

Foam is water-resistant and does not wash out, so it holds the soil in place. If the slab settles again, the written warranty covers the work.

Does the work come with a warranty?

Yes, every job is backed by a written warranty, and the terms go into your estimate before the work starts. Ask for the terms when you call.

Hollywood Concrete Leveling & Repair serves Hollywood and Broward County.

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