Is your concrete sinking? Unstable concrete and sinkholes are a common problem in Floridian soils, and it can cause cracks and holes all over your property. Today is all about the best way of fixing sinkholes, and whether mud jacking or foam injections work best. Here’s what you should know about it!

Why does concrete sink?

Sinking concrete is a common issue here in Florida. The main reason why concrete sinks is because of unstable soil. Our sandy soil tends to settle over time, and the high water tables can create large air pockets under your slab. Eventually, this causes concrete to crack, break and sink.

Other reasons for cracked or uneven concrete slabs are water damage (due to broken pipes, for example) or lack of support for the slab (if part of it isn’t over soil).

To fix sunken concrete, we need to deal with two issues:

  1. Filling up current air pockets and settled spots

  2. Stabilizing the soil underneath the slab

To do this, most crews will give you two options: mud jacking or poly foam injections. But what are they and which one should you choose?

Mud jacking: how does it work

Mud jacking, also known as concrete leveling, is the process of injecting a concrete “slurry” underneath the affected slab to make it level. To do this, the crew will drill small holes into the slab. Then, the slurry is pumped into the holes and left to dry. Concrete slurry is a liquid mix of sand, cement and other ingredients. When injected beneath the slab, it can raise and level it.

This is a good option to avoid tearing out and completely replacing a concrete slab. However, the concrete slurry has relatively longer drying times, so it cannot get solid quick enough to lift very heavy or load-bearing slabs. It is also heavy, so unstable soils might settle down even more, creating air pockets that will destabilize your slab after the work is done.

Mud jacking is only effective on smaller slabs that have a relatively lighter weight, where the soil isn’t overly unstable.

Foam injections: how do they work

Foam injections follow a similar procedure to mud jacking, but uses a completely different compound to support the slab. After drilling penny-size holes into the uneven concrete, polyurethane foam is injected underneath.

Polyurethane foam is pumped in as a liquid, but as we inject it, it expands into a lightweight, solid and very strong foam. Because it expands on its own, it’s great to fill hard to reach air pockets in the soil and perfectly fills cracks.

Poly foam injections are nowadays the preferred method for fixing sinkholes and uneven concrete. High-density polyurethane is strong enough to lift very heavy concrete slabs, and works even in load-bearing areas. Plus, because it is a synthetic waterproof product, poly foam holds up better than mud jacking to weather damage and can be used in projects near the water.

This method has a ton of benefits: it supports concrete, levels up slabs, it’s flame-retardant and water resistant. Being so lightweight, it won’t compact your soil even further, unlike mud jacking that tends to make soil settle over time. Poly foam injections are also useful to give structure to unstable soil: it adds no extra weight and binds the soil together, meaning your slab will have a proper base to lie over.

Foam injections vs mud jacking: which one is better?

As with most tools for concrete repair, there is no one-size-fits-all answer. Some projects are suited for both, but others will only work with a specific technique.

In our experience, mud jacking has a limited application scope. This means fewer projects will require this technique. As we’ve mentioned, mud jacking adds extra weight to the soil, which might weaken the ground even more. This can lead to sinking over time!

We would only use mud jacking in these cases:

  • Concrete that is still in good condition but no longer level

  • Smaller slabs that weigh less

  • Concrete that doesn’t need to be used right away because of longer drying times

  • Projects that won’t have contact with water

On the other hand, poly foam injections can be used in a wider range of settings. Our team has used “poly jacking” for sidewalks, driveways, pool decks and many other uneven concrete projects. In our experience, poly foam injections work better for:

  • Projects where time is essential: there is almost no waiting for it to dry (you can put weigh on the concrete after 30 minutes). Poly foam is also faster because there is minimal cleanup. Unlike concrete that we have to mix and then scrape off, after we’re done with poly foam we’ll just dust off the surface and everything will look as good as new.

  • Fragile concrete: poly foam adds almost zero extra weight, avoiding further damage to the concrete slab. Try using poly foam to even out your concrete instead of pouring anew!

  • Heavy or load-bearing slabs: polyurethane expands to reach every nook and cranny, and then dries into an incredibly strong foam. The high density of the foam can lift very heavy slabs and offers further support to load-bearing concrete.

  • Concrete or soil that will be in contact with water (like pool decks or beachside properties)

  • Large sinkholes: poly foam is a quick and cost-effective way of filling up sinkholes and providing a stronger structure to the soil.

  • Projects where looks are important: poly jacking requires fewer drilling holes than mud jacking.

  • Poly foam injections also last much longer, compared to the usual 2 to 3 years for mud jacking projects.

In our experience, poly foam injections provide better value to our clients, since the job lasts longer, it looks better and can withstand contact with water. A clear winner in our book!

If you’re still unsure about how to fix your concrete, we’re here for you! Let us know your questions and our expert team will give you tailored advice.

Updated: Sep 13

So, you’ve got a quote and they suggested polyfoam injections to fix your concrete. What does that even mean?! No need to worry! Here’s everything you need to know about it (and whether or not you should use it at home).

What are polyfoam injections?

Polyfoam is short for “polyurethane foam”, a chemical compound that is liquid but then it expands and dries into a solid, very strong foam.

Because it starts in liquid form, polyurethane can be injected and perfectly fills cramped, hard-to-reach spots underneath pool decks, foundations or sidewalks. And to seal it off (ha!) polyfoam is environmentally inert, meaning after application it isn’t dangerous to the environment, pets and humans.

Polyfoam injections can be used just about anywhere with these conditions: it supports, it levels up, it’s flame-retardant and water-resistant, meaning ADP polyfoam injections can even fix concrete near water without issues.

Benefits of using foam injection

Polyurethane truly is the best, fastest way of leveling concrete around the home. APD recommends using polyfoam to most of our clients because:

It’s cheaper:

Tearing up and redoing your sidewalks or pool deck can be very expensive, and the natural erosion process means new concrete can still sink eventually. Instead of tearing up your slab, polyfoam injection lets you keep using perfectly good concrete and fix sunken spots.

Foam is lightweight:

The main reason why concrete sinks and sidewalks start wobbling is because the soil underneath is weakened by erosion, compacted or settled. Polyfoam adds strength and stability without the weight of traditional mudjacking. This means your soil won’t degrade even more.

It’s clean:

The beauty of polyfoam injections is there’s virtually no clean-up after. Just some remaining dust can be quickly cleaned up with a broom.

It’s fast:

After application, you can walk or even drive over the fixed spots in just an hour. Unlike concrete, there’s no need to wait for days until it dries!

The choice is clear: if your concrete can be fixed with foam injections, it’s the best option!

How does it work?

Polyurethane injections stabilize your concrete. Depending on your needs, APD can either use injections to level a slab or even to bind the soil to strengthen the material below smaller concrete slabs. Although the exact procedure will change depending on the goal of the project, here’s how it works:

Step 1, Evaluation:

Depending on your needs, either an expert team or an engineer will take a look at the issues to figure out what are the causes.

Step 2, Designing an action plan:

APD uses different polyurethane types depending on the weight of the structure, the stability of the soil underneath, and other factors like nearby water. At this point, APD can correctly suggest the type of polyurethane foam that best fits your needs.

Step 3, Drilling and application:

Depending on your project, this can be a fairly quick process. Our team uses poly foam injections mainly with two different purposes: to fill voids in the soil beneath your concrete, or to stabilize the slab. Filling voids means your soil has already settled and there are “holes” or air pockets that will be replaced by polyfoam. For slab stabilization, we can fill the gaps but also inject polyfoam into the ground to bind the soil together and provide better support.

Step 4, Cleanup:

This is one of the best parts of polyfoam injections: cleanup is incredibly fast! Minutes after the job is done, APD only need to sweep the slab and that’s it. The mess is minimal because the concrete is drilled then patched.

Types of poly foam for concrete repair

Our team will use specific types of polyfoam injections depending on the location of the project, your needs and the state of the concrete. But regardless of the application, APD always use polyurethane foam that is 100% environmentally safe and 100% hydrophobic, meaning water won’t affect the job.

Most of the time, APD use one of these polyfoam types:

  • HF202: This is a hydro-sensitive polyfoam designed for jobs where water or consistent moisture is present. It sets up in the presence of water and maintains stability in wet environments. It’s great for residential concrete and sinkhole repair.

  • HF202FAST: Because it has a low density and quick reaction time, this polyfoam is used it to lift smaller cement slabs. Of course, it’s also hydro-sensitive and stable in wet environments.

  • HF402: This type is hydro-sensitive as well, but denser than the HF202 types. It also sets up when water is present, and maintains remarkable stability in wet environments like pools or ponds. Our team uses it for residential, commercial and industrial foundation and concrete repair.

  • HF402FAST: This one has the same strength as the HF402, but with the speed of HF202. This type of polyfoam is used for deep foam injections that need faster reaction times, so it’s great for lifting slabs.

Sunken driveway before polyfoam injection
Before APD polyfoam injection repair

Polyfoam injections: what can you fix?

If you’ve got a foundation with minor damage, wobbly sidewalk or your concrete slab has just seen better days, polyfoam injections are probably a great idea. Polyurethane injections are successfully used for:

Foundation and sinkhole repair:

If your home is showing cracks on the walls or there are sinking spots, polyfoam may be used to provide soil stabilization and give even more support to other foundation repairs like underpinning.

Trip hazards:

Uneven concrete slabs are just accidents waiting to happen. Our team uses polyfoam to stabilize the ground under any concrete slab, level it and patch up any cracks to keep everyone safe.

Pool deck repair:

Do you have an uneven pool deck? A few deep polyfoam injections will make your deck walkable again. We use polyurethane to quickly stabilize and raise concrete slabs around your pool so it looks as good as new.

Sidewalk repair:

If your sidewalks are unstable or wobbly, you’re probably dealing with settled soil. Polyfoam can fill those voids to provide a secure base and keep your sidewalks level. APD can also fix sidewalk cracks by lifting the slab with polyfoam injections and patching it up.

Crawl space repair:

Sometimes, cracks in your walls might not be related to your foundation but to your crawl space! APD uses polyfoam to strengthen the soil below your crawl space and give more stability to your entire home.

Seawall repair:

Since we only use hydrophobic polyfoam, it’s a great option to fix seawalls that could be exposed to the elements.

We hope this info gives you a better idea of what polyfoam injections are and how they are a great tool to fix your concrete. Have you ever used this option around your home?

House supported by helical piers before construction

Are you planning on building in Florida? Florida is a beautiful state, but soil stability could wreak havoc on your future building! No worries! APD Advanced Stabilization know how to create a solid base anchored to firm ground. Consider installing helical piers! Using pilings on new structures will boost load-bearing capacity and ensure long-term stability. Do you know about this method?

What are helical piers?

Basically, "helical" just means screw-shaped. These piers are also known as screw pier foundations or screw piles. Helical piers ensure your foundation is stable and ready to support your building. Helical piers can be used before construction or for lifting and supporting structures that are sinking.

Florida's loose and sandy soils make traditional foundation installation more difficult. Sandy and loose soils are not great for foundations because it tends to move and shift with the weight of the house on it. Helical piers will be placed in the looser soil until they reach a more stable layer. Installing helical piers before building can save you money and headaches from dealing with a sinking foundation.

Still wondering about taking the leap? Here are some of the reasons why APD Advanced Stabilization recommends them.

Benefits of using helical piers in new buildings

While helical piers can also be used after foundation problems appear, it’s almost always better to install them in the pre-construction phase. The benefits of using helical piers include:

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Perfect for sandy soil

Florida is a beautiful state, but the loose, granular soil and high water tables can seriously limit the size and location of your building! This is especially concerning if you plan on doing a 2-story home or a larger building. However, helical pilings basically eliminate the possibility of severe foundation troubles down the road. By drilling the piers during the pre-construction phase, APD is able to anchor your building to stable soil no matter how deep or shallow it is.

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Protect your home from settling and sinkholes

This is the most obvious benefit! Helical pilings for new constructions provide a stable base for your home’s foundation. As a preventative measure, APD will be able to place the piers strategically throughout the entire area of the future foundation when installation is done. This ensures an efficient and safe distribution of the final weight and anchors your building to the stable soil deep underneath.

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Fast installation

With piling, there’s no need to wait weeks for concrete and deal with third-party delays. You also won’t have to wait for concrete to cure, and raining won’t alter the schedule either. Because steel components and hydraulic installation are used, APD can install helical piers fairly quickly and in any weather! Plus, once everything is drilled and done, you won’t need to wait. Piers can be used to their full load instantly, getting you building and above ground quicker than traditional construction methods.

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Great for heavy buildings

Are you planning on building a large commercial structure? Or maybe just a home with several stories? Whatever the case, heavy buildings in Florida need an especially sturdy foundation. Overall, helical piers improve the load bearing capacities of heavy structures and foundations, even in sandy Florida soils!

Helical pilings transfer the load from the soil surface deep into the ground, where the piers are anchored to stable soils. This technique has been used to support bridges, retain coastal walls and it will make sure your new building is as stable as possible.

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Precise application

Unlike traditional foundations, helical piling doesn’t use a one-size-fits-all approach. Instead, after evaluating the soil and the project, APD will create a customized plan that ensures pilings are drilled in active layers of soil at every load-bearing point. Plus, depending on the slope of the landscape and the configuration you need, They will organize the pilings to ensure efficient load distribution throughout. This lowers overall costs throughout, since your contractor won’t have to reinforce the foundation mid-way through the project.

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Effective in almost any terrain

Florida soils are notoriously difficult to build in. This gets even worse in new coastal buildings where the soil is extremely sandy and active. Luckily, helical piling can be installed in almost any terrain and even in landscapes that have different soil types under the same foundation. This means the application can be tailored to your needs, depending on the size of the project, the final weight of the structure and the quality of the soil at every spot.

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Ideal for limited access sites

Unlike traditional methods, helical pilings don’t need huge equipment to be installed. APD Advanced Stabilization uses hydraulic machinery of moderate size that can easily fit in smaller spaces or terrains with limited access. The entire installation process is also cleaner overall, since the only action is drilling into the soil. In our experience, helical piers are the best option for projects where accessibility and speed are key!

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Prevents soil disturbance during installation

Sandy, unstable soils can be easily disturbed during construction projects. This can make the soil even harder to work with, and provide an inadequate foundation to any building. By limiting the amount of soil that is being moved, APD will also save the existing soil as much as possible. This allows for installation even in so-called active soils (soils that are move with moisture).

Can helical piling be used for foundation repair?

Yes! This method quickly raises settled concrete and provides deep foundation support to unstable foundations. And given the considerably smaller equipment, and immediate effectiveness after installation, helical piers are one of APD's preferred ways of providing extra support to pre-existing buildings.

Final thoughts...

Helical pilings are an efficient and affordable option for residential and commercial projects alike! Especially in Florida’s problematic soil, this is the best way to properly anchor your building, stabilize and support your investment over the long term. Whether you are working on a new building or want to repair a pre-existing foundation, consider helical piers as an option!