Mat Slab Foundation

Many places have soil that varies in density. Some places the soil is just very soft overall.  This leaves many contractors searching for a solution.  Commercial buildings undergo more wear and tear than normal residences and their foundations need to be constructed to withstand those challenges and last.


Soil that is high in clay content tends to expand and contract as the clay absorbs and releases water from the environment. Expansive soils damage foundations and concrete floor slabs, causing more financial loss than hurricanes, floods, tornadoes and earthquakes combined. This leaves builders trying to figure out what type of foundation is suitable for expansive soil. Trying to find what foundation for commercial buildings is suitable for your build is very important.


Building on expansive soil can be tricky, knowing the foundation types for commercial building, their strengths and weaknesses can take some of the stress and guesswork out of the process. Once you see cracks in the brick and foundation and floating walls, you are likely looking at massive repair bills. It is in your best interest to choose the best foundation for expansive soil with your original construction.  


T Shaped Foundation



The T Shaped concrete foundation is the most common, but requires more labor costs to construct. It is placed deeper in the soil below the frost line.  The deep foundation allows it to hold heavier loads and provides stability


Slab on Grade Foundation


Another commercial building foundation system is the slab on grade foundation. This commercial foundation is used in areas where the ground does not freeze.  It is a concrete slab several inches thick and is laid directly on land where the soil has been compacted. It is not able to hold heavy loads like the T shaped design and is very vulnerable to cracks and damage if used on clay soil.


Waffle Mat Foundation 

Wafflemat, the leading foundation techology

A third option is the waffle mat foundation.  Many feel this is the best type of foundation for clay soil, because it is designed not to be damaged by expansive soil.  

The wafflemat system has void areas where moisture can escape and soil has room to expand and contract. This eliminates foundation problems caused from cracking and lift. The waffle slab is a better fit for expansive soil classifications than normal flat slabs, while staying within the same cost ranges.


The waffle formwork is also thicker than a regular mat foundation slab.  Some disagree on how thick a concrete slab should be for a commercial building foundation plan. With slab on grade foundations, concrete thickness is between 4-6 inches, the wafflemat foundation is between 12-14 inches thick. 


Many concrete slab contractors agree that the waffle slab form is the best foundation for expansive clay soil out of all commercial building foundation types. It is always most advantageous to get the foundation design correct during the original build.  The cost of commercial building foundation repair and replacement can be astronomical. 


The waffle concrete slab design is your best bet for an original build or a replacement system. 


To speak with an expert who can help you with your expansive soil problems and solutions, reach out to one of the representatives at Wafflemat today.  They will be happy to fully inform you of all the advantages Wafflemat foundation construction has to offer.