Problems With Self-Leveling Concrete (and When to Use Alternatives)

Self-leveling concrete sounds like a dream: pour it, let it flow, and end up with a perfectly smooth surface. 

But is it really that simple? Not always…

Self-leveling concrete (also called self-leveling underlayment) is often used to smooth out dips, waves, or uneven spots before laying new flooring.

At A-1 Concrete Leveling, we don’t apply self-leveling compounds, but we do get a lot of questions about them. Below, we’ll break down the four biggest problems homeowners face with self-leveling concrete, plus better alternatives when the goal is long-term slab repair.

TL;DR

Self-leveling concrete can hide uneven spots, but it comes with risks: cracking, short working times, DIY difficulties, and failure to address the root cause of slab problems. It’s useful for interior dips before installing tile or hardwood, but not a long-term solution for settled slabs. In these cases, professional concrete leveling is the better option.

In This Article

• Problem #1: Cracking and Crumbling
• Problem #2: Difficult for DIYers
• Problem #3: Short Working Window
• Problem #4: Underlying Issues Aren’t Fixed
• When Self-Leveling Concrete Actually Makes Sense
• Alternatives to Self-Leveling Concrete
• FAQs

Problem #1: Cracking and Crumbling

One of the biggest issues with self-leveling concrete is how prone it is to cracking. Common reasons include:

• Poor surface prep: If the slab isn’t properly cleaned, primed, or ground, the new layer won’t bond and will eventually flake or chip away.
  
  
• Movement underneath: Slabs naturally shift as soil erodes or settles. A thin topping layer doesn’t move with the slab; it cracks instead.
  
  
• Pre-existing cracks or joints: Self-leveling compounds almost always crack where the slab is already moving.

Eliminate Sinking Concrete

5 Ways To Fix Settled Concrete Slabs

Discover the options you have when it comes to uneven concrete - indoors and outdoors.

Problem #2: Difficult for DIYers

Despite the simple-sounding name, self-leveling concrete isn’t easy to get right. It requires:

• Exact water ratios. Too much = weak and runny. Too little = clumpy and unworkable.
  
  
• Controlled conditions. Temperature and humidity directly affect curing, especially outdoors.
  
  
• Skill with timing. Beginners often mix too much at once and run out of time before it sets.

For this reason, it’s not an ideal DIY solution, especially in visible or high-traffic areas.

Problem #3: Short Working Window

Most compounds give you only 15–30 minutes from mixing to pouring and finishing. This means:

• Little time for correcting mistakes.
• High risk of uneven spots if you work too slowly.
• Stressful application if you don’t have help on hand.

While the fast cure time is convenient for quickly moving on with flooring installation, it can make the process unforgiving.

Problem #4: Underlying Issues Aren’t Fixed

Perhaps the most important point: self-leveling concrete doesn’t solve structural problems.

• If your slab is settled or has voids underneath, topping it won’t stop future sinking.
• Cracks and movement beneath will eventually transfer through the surface layer.

Pro Tip: If your concrete is settled, you’ll likely need to lift it back up with professional concrete leveling services.

Eliminate Sinking Concrete

5 Ways To Fix Settled Concrete Slabs

Discover the options you have when it comes to uneven concrete - indoors and outdoors.

When Self-Leveling Concrete Actually Makes Sense

There are situations where self-leveling compounds are a good fit:

• Dips in interior concrete slabs. For example, dips that make tile or hardwood installation tricky.
  
  
• Small cosmetic improvements. Such as smoothing a basement or interior garage slab before coatings.
  
  
• Not for carpet. Carpet and padding already mask dips, so self-leveling is rarely needed.
  
  
• Not for exterior slabs. Freeze-thaw cycles and weather exposure quickly cause failure outdoors.

Alternatives to Using Self-Leveling Concrete

If your concrete is sinking, cracked, or uneven because of soil settlement or erosion, you’ll want a fix that addresses the root cause.

Related Resource: 5 Best Methods to Fix Uneven Concrete

Should You Use Self-Leveling Concrete?

If you’re considering self-leveling concrete, make sure you understand its limits. For interior floor prep, it can work well. But for structural issues like sunken slabs, cracks, or exterior damage, you’ll get far better results with professional services.

At A-1 Concrete Leveling, we specialize in:

• Concrete leveling to lift sunken interior and exterior slabs
• Concrete caulking to seal cracks and joints
• Concrete cleaning and sealing to protect against future damage

Request your free on-site estimate today and let one of our experts recommend the best option for your slab.

Still Deciding?

• Can You Pour Self-Leveling Compounds Over Existing Concrete?
• How To Fix Uneven Concrete: 5 Ways
• How Much Does Professional Concrete Repair Cost?

Frequently Asked Questions

Is self-leveling concrete durable?

Not always. It’s more brittle than traditional concrete and can crack if the slab below moves.

Can I use self-leveling concrete outside?

It’s not recommended to use self-leveling concrete on exterior slabs. Outdoor concrete expands and contracts with freeze-thaw cycles, causing the compound to chip away quickly.

How thick can self-leveling concrete be poured?

Most products have a minimum and maximum thickness range (often ⅛" to 1½ "). Exceeding that range can cause failure.

Should I use self-leveling before laying carpet?

No, you usually do not need to use self-leveling compounds before installing carpet. Carpet padding hides most dips, so adding self-leveler is unnecessary unless there are dramatic dips and uneven texture in the subfloor.

What’s the best alternative if my concrete is sinking?

Professional concrete leveling is the best option for sinking concrete, both inside and outside, because it fills voids beneath the slab and restores support while lifting the slab.