Natural Limestone Grout - VS -
Poly-Foam, Why Now?
What’s the Back-story?
Why is PolyFoam en vogue and is it the “latest & greatest” technology? The simple answer is no. It is not a new technology.
The industry has merely found a way to capitalize on selling the chemical components on a consistent basis to its franchisees or end users as a source of ongoing revenue.
On the other hand, A-1 Concrete Leveling can purchase crushed limestone from a number of different sources and isn’t reliant on one single source for its material.
It is our intention to educate the consumer so that they can make the choice as to what process best suits them and their property. There are some benefits to using foam in more industrialized or commercial highway applications performed by those who have multiple years of experience and training handling these types of chemicals and their proper mix of them, but for our purposes in serving your home or business we will stay committed to using a tried and true environmentally safe material that has been successfully utilized in resolving just about every sinking concrete situation we have encountered in over 10+ years of service in Western New York.
Our Experience & Research
The Benefits of Limestone
1) 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.
2) DOES NOT ADD WEIGHT TO THE BASE CAUSING FURTHER SINKING
One of the pieces of mis-information 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
3) SPREADS BETTER THAN
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.
4) 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 giving us on the spot versatility. We can control the lift throughout the entire leveling process.
5) 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.
6) WILL NOT ATTRACT INFESTATION
We have never in 10+ 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.
7) 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.
Our Concerns About Chemical Based Polyurethane Foam
1) CHEMICAL BASED MATERIAL
The components of PolyFoam only become “inert” when mixed precisely and exactly right, otherwise individually are toxic. If the individual components spill due to a loose connection, bad O-Ring or worn tool, the exposed items will need replaced or at a minimum painted. The chemicals cannot be washed off.
How Is It Made?
The product is formed by reacting a polyol (an alcohol with more than two reactive hydroxyl groups) with a Di-Isocyanate or a Polymeric Isocyanate in the presence of Amine based catalysts and additives. Amine catalysts are widely employed in foundry and polyurethane foam operations. These highly reactive Amines have been associated with graphic disturbances in vision and other respiratory health effects.
If the “A Side” and “B Side” chemicals that come together at the point of injection under the concrete are not properly calculated, there is potential for what is called “Off Gassing” or the airborne release of the reactants to occur for a span of time after the project has been completed
2) LIMITED SPREAD OF MATERIAL / PILLOWING
Voids that produce sinking slabs are usually never evenly distributed or consistent. They have peaks and valleys and the visual symptom at the ground level is never the entire story as to what is going on underneath. Foam sets up relatively fast and due to that nature, the foam material often fails to spread evenly enough to re-establish a significant area of the base. Foam is done in a series of injections with the second one setting up under the first injection and so on (like a stack of pancakes). This creates a pyramid or localized pillar type effect under the area that has sunk to raise it back up. The issue at ground level may seem to have been solved but the lack of spread underneath puts the rest of the slab at risk for future cracking where there is an unfilled void and no material.
3) CONTROLLING THE LIFT
Foam reacts and expands with moisture. Lifting concrete with foam often requires a “stop-short” approach. Due to the potential of unseen moisture under a slab, lifting and stopping just shy of level is usually the means to guard against over lifting. Once a slab is over lifted it is an irreversible situation with the more expensive option of replacement being the only customer recourse. Due to the relatively fast set up nature of foam, tamping a slab back down once over leveled is incredibly difficult.
4) ONLY INJECTED THROUGH 5/8” HOLES
For smaller projects this is acceptable but for more detailed work or larger slabs additional 5/8” holes may be needed to achieve the desired outcome. Our customers always prefer less holes being drilled via our 1” hole delivery method.
5) PERMANENT SOLUTION with a potential caveat
Foam will provide a permanent solution just like our limestone grout if there is no further ground erosion or compaction. However, we have seen foam adhere/glue itself to the slab and /or adjoining foundation that make any additional lifting potentially impossible without causing damage to the slab
6) RISK FOR INFESTATION
Ants create tunnels in the pockets of the foam and If enough of this material is either devoured or removed by any unwanted tenants, the slab will be at risk for eventual collapse.