Pressure Grouting VS. Polyurethane Injection

When a foundation settles due to known or unknown circumstances, the owner needs to have it repaired. Ewing & Ray Foundation Services have been in the foundation repair business for over 51 years and utilizes helical piers as lift points for the foundation repair. Once the foundation is lifted and stabilized, there is a space between the earth and the slab which is often referred to as a void. A “slab on grade” foundation system is not designed to have a void between the concrete slab and the earth.

When void exists between the concrete slab and the earth, there are several potential problems which can arise. One is there is stress placed on the concrete slab which was designed to be in constant contact with the earth. The results can be a sagging of the concrete slab or the concrete slab can fail because of the stress. Another issue which could arise because of a void is the occurrence of standing water.

Pressure Grouting is one method for addressing these voids.

The other alternative is to use High Density Polyurethane Foam, “Foam”, to fill the voids underneath the concrete slab. There are advantages to using Foam to fill voids. The Foam we use goes in at a higher pressure and is more viscous than grout so it can cover more area and get in smaller places. It is injected through a 3/8” hole compared to the larger holes used in grouting, so less damage to the foundation. Our Foam expands up to 24 times in volume in 15 seconds and is 90% cured in 15 minutes, so the area is usable in much less time. Besides the fact that the holes are smaller, the process does not take as long as grouting and the setup and cleanup time is vastly shorter.

In conclusion, Pressure Grouting is always needed after the foundation is lifted and a void is left behind. But there are times though, that using Foam is faster, easier and is a better option.