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.

Potential Risk

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

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2) LIMITED SPREAD OF MATERIAL / PILLOWING

or PILLARS

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.

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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.

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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.

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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

or foundation.

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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.

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