Can You Pour Self-leveling Concrete Over Existing Concrete?

If you’ve heard that self-leveling concrete is an easy way to fix common concrete problems and you’re considering using it for yours, it’s important to know exactly what you’re getting yourself into in order to make the best decision for yourself and your situation.

A-1 Concrete Leveling has been repairing concrete for over 30 years, and in this time we’ve seen a lot of good applications for self-leveling concrete, as well as some that have crumbled away and deteriorated prematurely.

This article will walk you through how self-leveling concrete works, discuss when you can use it over existing concrete slabs, provide some best uses for self-leveling concrete, and give you some alternatives to consider if using it for settled concrete slabs.

How Does Self-Leveling Concrete Work?

Self-leveling concrete is a cement-like compound similar to concrete, but it is much thinner and flows easily. When mixed with water, it can be poured over existing concrete slabs where it will spread and even itself out, creating a level surface.

Each self-leveling compound is different and cures at varying timelines; some are ready for use within 12 hours, and others require waiting 24-48 hours. Heating, ventilation, and other similar factors where the self-leveling concrete is applied can also influence the time it takes for the compound to dry.

Using Self-leveling Concrete Over Existing Concrete Slabs

Self-leveling concrete is designed to be used over existing concrete to achieve a flat surface, but in order to ensure a quality application that will last, the existing concrete must be prepared beforehand.

To prep the area, the concrete must be cleaned, primed, and any holes must be patched to avoid allowing the self-leveling compound to leak out. Extra care must be taken to remove any loose debris, chipping concrete, stains from oil or grease, or dried paint, as these imperfections can cause the self-leveling concrete to chip or deteriorate prematurely.

Best Uses for Self-leveling Concrete

When concrete is poured, sometimes it can be finished with dips or other imperfections. Self-leveling concrete compound is intended to even out these dips and inconsistencies in the concrete’s surface, especially before installing new flooring. 

Many people try to use a self-leveling concrete compound in an attempt to relevel concrete slabs that have settled. In this case, the compound has to be applied in a thick layer and will likely end up crumbling away. Also, using a layer of self-leveling concrete won’t address the actual reason why the concrete is settling, so there is a possibility that the slab itself will keep settling.

With this in mind, the following is a list of the best use cases for self-leveling concrete:

• Filling in dips in the surface of concrete, like concrete floors in preparation for flooring
• Interior projects, as the temperature fluctuations outside can cause premature cracking
• Pours ¼ inch deep or less, although this can vary by compound

Alternative Options to Self-Leveling Concrete

If your concern is not smoothing your concrete’s surface, but rather you have concrete slabs that need to be releveled, there are far better options to achieve that goal. Here at A-1, we recommend concrete leveling, and in some cases, concrete grinding.

• Concrete Leveling

Concrete leveling is a quick and convenient process that works by lifting settled concrete slabs as close as possible to their original position. Small holes are drilled in strategic locations in the affected area, then a strong and durable leveling compound is pumped under the slab, lifting it and creating a new, solid base for the concrete to rest on.

Concrete leveling can be done indoors or outdoors, and in most applications where self-leveling concrete would be used to level sunken floors. However, concrete leveling does not change the surface of the concrete, so if the slab is both sunken and has dips, self-leveling concrete may still be required to achieve a smooth surface.

• Concrete Grinding

Concrete grinding works by sanding down the surface of a concrete slab to create an 
even grade. Concrete grinding can be a cheap and easy way to eliminate trip hazards, 
but it’s not recommended in all situations because it exposes the concrete to potential damage.

In place of using self-leveling concrete to relevel sunken concrete slabs, concrete grinding may be an alternative to even out the area and create a level concrete surface.

What’s Next?

Now that you know about what self-leveling concrete is and when to use it, you’re ready to start your concrete project, or look into the alternatives available to you for fixing sunken slabs, like concrete leveling.

You want your repair to stand the test of time, so making sure you’re using self-leveling concrete correctly and for the right application can save you lots of headaches and additional costs down the road.

A-1 Concrete Leveling offers free onsite consultations and cost estimates, so if you want to know more about your repair options, click the link below to request an appointment!

If you’re interested in learning more about concrete leveling or other concrete repair methods, check out these topics from our Concrete Academy:

• How long does concrete leveling last?
• What influences the cost of concrete leveling?
• The Cost of Doing Nothing: Concrete Repair

self-leveling concrete

Sarah Etler

November 30, 2022

Sarah Etler joined A-1 Concrete Leveling after receiving her Bachelor of Arts degree in English from Northern Kentucky University. As A-1's Digital Content Manager, she works closely with industry experts to produce content that will best answer questions related to concrete repair and maintenance practices. Sarah loves living a life full of discovery and is excited every day to see what new things she can learn and share with those around her.