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How To Level A Concrete Slab Via Poly Foam Injection

How To Level A Concrete Slab Via Poly Foam Injection infographic
How To Level A Concrete Slab Via Poly Foam Injection infographic
Are you looking for information on how to level a concrete slab? If so, you’ve come to the right place. We’re going to tell you what we believe to be the best way to level a concrete slab. 
The good news is most unlevel concrete slabs don’t need to be replaced by digging up the old slab and pouring a new one. (Pouring a new slab is expensive and time-consuming because new concrete needs to dry and cure, which means there’s a certain amount of downtime whenever you dig up and replace a slab.) Today, uneven concrete slabs can be easily releveled via a quick, minimally-invasive repair procedure that usually only takes a few hours. The slab is ready for use as soon as the repair is complete. 
In this article, we’re going to go over why concrete slabs become unlevel, how to level a concrete slab using poly foam injection, and why poly foam is better than replacing the slab. 

Why Concrete Slabs Become Unlevel

Simply put, concrete slabs become unlevel because concrete doesn’t last forever. At some point, it will start to deteriorate due to normal wear and tear, weather conditions, soil movement under the slab, soil erosion, invasive tree roots, or something else.

As a concrete slab deteriorates, voids can form under the slab. When the slab settles into these voids, it will become uneven. It could even crack.

Unlevel Concrete Slabs Are a Trip Hazard and a Liability

You don’t want uneven concrete slabs on your property because they’re a trip hazard and a liability. If someone trips, falls, and breaks something, you could find yourself on the receiving end of a nasty lawsuit.

Fortunately, as you will see in the next section, repairing an uneven sidewalk, driveway, pool deck, etc., is easy. The slab can be leveled in just a few hours. Therefore, there’s no reason not to fix your uneven concrete slab.

how driveway leveling works epp foundation repair infographic

How to Level a Concrete Slab via Polyurethane Foam Injection

Leveling an uneven concrete slab via polyurethane foam injection is a quick, minimally-invasive procedure that will have your sidewalk, driveway, pool deck, or some other type of concrete slab fixed and ready for use in just a few hours.

When using polyurethane foam injection to level an uneven concrete slab, the general procedure is as follows:

  • Small, dime-sized holes are drilled into the slab. Don’t worry. These will be patched later with a compound that matches the color of the slab.
  • Polyurethane foam is injected under the slab through the holes. It rapidly expands to fill any voids under the slab. As this happens, the foam also lifts and levels the slab.
  • After the slab has been lifted and leveled, the holes are patched using a compound that matches the color of the concrete. When the repair is complete, the holes are virtually invisible.

Leveling a sidewalk, driveway, pool deck, etc., using polyurethane foam injection usually only takes a few hours. You’ll be able to use the slab again about 15 minutes after the repair has been completed.

Read more – how to level a concrete floor that slopes.

Photo of concrete lifting before and after

Why Polyurethane Foam Injection Is Better Than Replacing the Unlevel Slab

Polyurethane foam injection is better than replacing an uneven slab for various reasons, including the following:

  • Replacing an uneven slab means digging up the old slab and pouring a new one. This is time-consuming and significantly more expensive because it’s more labor-intensive.
  • Freshly poured concrete needs time to dry and harden (cure). That means there will always be a certain amount of downtime until the new slab is ready for use. For example, the typical amount of wait time before you can drive on freshly placed concrete is one week. With poly foam injection, there is no downtime. Fifteen minutes after the repair is complete, you can walk and drive on the slab.

Polyurethane foam injection is also better than lifting an uneven slab via a procedure known as “mudjacking.” Now, you’re going to run into people who claim that mudjacking – an older method of leveling concrete slabs – is superior. This article answers that claim: Concrete Lifting Foam Beats Mudjacking Hands Down For Fixing Uneven Slabs.

The Cost of Leveling a Concrete Slab

The cost of leveling a concrete slab will depend on a few things, including your geographical location and the extent and severity of the settlement (i.e., unevenness). The extent and severity of the settlement determine how much polyurethane foam will be needed to get the slab lifted back into place.

Here at Epp Foundation Repair – as of July 2022 – the starting cost for leveling a concrete slab using polyurethane foam injection is $1650. Depending on what’s necessary, that could rise to $6000 or more. (Keep in mind that the price of this repair procedure might have changed by the time you read this article.)

While mudjacking is less expensive than leveling an uneven slab using polyurethane foam injection, it’s more likely to sink again, which means another repair. This is because mudjacking uses a heavy cement slurry to lift the slab. Mudjacking adds a lot of weight to soil that was already having trouble supporting the slab. In contrast, poly foam is extremely lightweight.

If you‘ve been wondering how to level a concrete slab on your property, we have an answer: polyurethane foam injection. Contact us today for an inspection and estimate.


Dave Epp

Dave is the President at Epp Foundation Repair with over 27 years of experience in the industry. Dave has worked on thousands of foundation, basement, concrete, and crawl space repair projects since 1993. Dave is involved in several civic and church organizations and enjoys coaching youth sports, mainly football, golfing, and elk hunting.



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