Concrete Leveling

"Hi Carl,

My house has concrete slabs in the back yard which make up my patio.

I live in NY State and the constant changing weather has caused the slabs closest to the house to heave inward so that any water whether it is melting snow, rain, or just washing off patio runs inward and sits at the foundation for hours and sometimes even days depending on the weather.

Is there a quick and fairly inexpensive fix for this or will I need to have it replaced?

Thanks, Nancy"

Hi Nancy,

Using a concrete slab for a patio is a good way & one of the least expensive ways to build a patio.

Unfortunately, nothing lasts forever, especially concrete slabs, without footings or a good gravel sub base.

Unprotected from frost and freezing ground, they heave and crack. They also sink when they are poured on non-compacted earth, such as near a house foundation.

In your case, an additional problem may occur due to the sinking, if it hasn’t already, and that is that the sitting water may eventually seep into your basement.

One solution I have seen work is slabjacking, also called mudjacking.

Concrete leveling or slabjacking (mudjacking) is a procedure that attempts to correct an uneven concrete surface by altering the foundation that the surface sits upon.

It is a cheaper alternative to having replacement concrete poured, and commonly performed at small businesses and private homes.

It is a process of leveling the concrete slab that can both raise, or float the old cracked slab back to its original position and create a new foundation of cement mortar or sand mix by injecting the mortar under the slab through a hole, under pressure.

Lifting a slab using this method can often be accomplished in a few hours.

Check for concrete leveling companies near you by Googling "concrete leveling" or "slabjacking".

Here’s a short video on the subject

However, you may need to have the slab(s) removed, the soil re-graded, compacted, and a gravel sub-base installed, and new slab(s) poured.

Compacting the soil won’t prevent this from happening again, but it will help add years to the lifetime of your patio.


If you do replace the concrete slab you may want to consider using permeable (porous or pervious) concrete when you redo the patio.

Permeable concrete allows water to pass through and drain into the gravel sub-base.

Permeable concrete uses the same equipment and process as common concrete. The difference is larger pea gravel and a lower water-to-cement ratio to achieve a pebbled, open surface that is roller compacted.

A good concrete subcontractor should be able to help you decide what to do.
Good luck,

Carl Heldmann