A-1 Richmond Grout Leveling VS. Foam Leveling
Superior Process - What does tried and true mean to you?
Natural Limestone Grout - VS - Chemical-Based Poly-Foams: Our Experience & Research
Many of our customers have asked about the use of chemical-based Polyurethane Foams and what our position is on that material and process. Hopefully, the following information will give you some insights as to why we primarily will always use Limestone Grout over chemical-based Poly-Foams.
As Richmond's original pioneer of concrete leveling, we have only used an environmentally safe Limestone Grout material to perform the lifting and leveling of sinking concrete. All of our solutions solve issues with what’s going on underneath. We have extensive knowledge and experience with the soil makeup of the Richmond, Virginia region. Drawing on that time in the field provides us a thorough perspective on how to properly resolve problems our customers deal with.

We equally pride ourselves in being an environmentally compassionate company and maintaining that trust is very important to us. Our customers feel vested in our approach knowing that they are utilizing a process that replaces lost earth due to erosion, poor drainage or compaction with more solid earth.
The Benefits of Limestone
- ALL NATURAL EARTH BASED PRODUCT—Limestone is actually used as the base when new concrete is poured. We feel if limestone is the perfect material for pouring new concrete on, it has to be an equally perfect material for filling voids, re-establishing the base, and lifting existing concrete that has sunk.
- DOES NOT ADD WEIGHT TO THE BASE CAUSING FURTHER SINKING—One of the pieces of misinformation that is circulating by foam competitors is that the weight of our material causes further sinking. Limestone is 80lbs per cubic foot, by comparison, an 80-pound child standing on one foot on top of a slab exerts 40 times more ground force vs what it takes to lift a 4x4ft slab with our material. Weight is a non-issue. 40+ years of leveling history, and mathematics, does not support any other conclusion.
- SPREADS BETTER THAN POLYURETHANE FOAM—The flow-ability of limestone allows for a superior result filling unevenly developed voids under concrete slabs. Re-establishing the entire base under a sinking slab is critical in providing a long-term solution that doesn’t put the slab at risk for future cracking where a void with no leveling material exists.
- CONTROLLING THE LIFT—Limestone does not over-react or over-expand, running the risk of “over-leveling” a slab due to moisture that is unseen underneath it. With limestone, we can change the flow-ability/viscosity of our material instantly so we can lift or stabilize as we want to, giving us on-the-spot versatility. We can control the lift throughout the entire leveling process.
- CAN BE INJECTED THROUGH 1” OR 5/8” HOLES—Our material can be injected through either size delivery method and the needs of the project determine which option is used.
- WILL NOT ATTRACT INFESTATION—We have never in 20+ years of limestone leveling seen any evidence of infestation of any kind taking place. Polyurethane foam, on the other hand, does offer the risk of infestation.
- PERMANENT SOLUTION—Once our material sets up and becomes hardened underneath the slab and if there is no more ground erosion under our material, our process provides a permanent solution.
In conclusion, while there may be times when polyurethane foam can do a similar job as our limestone slurry grout method of leveling concrete, in nearly every situation we are convinced you will receive a better solution with our method. Sometimes the latest and greatest isn't really all that great after all.
The concrete slab inside of the brick of my back stoop had tilted. A-1 did a fantastic job of correcting the problem. The team is prompt and courteous. Thank you for making the fix so easy and the cost so competitive!!!!