Polyurethane concrete raising consists of an environmentally safe liquid polymer foam that is injected through penny-size holes in the concrete and into the loose, unstable soils below. Through a chemical reaction, the high density foam expands to stabilize the loose soils and lift the settled concrete to make it level. After approximately 15 minutes the polyurethane material is fully cured and ready to return to service. The polyurethane only weighs about 2 pounds per cubic foot of material, which doesn’t add any additional, unwanted weight to an already failing substrate. Polyurethane foam is an inert, non-toxic, environmentally safe material that is made from recycled materials. It is impervious to moisture or decay ensuring that over time will not only be environmentally friendly, but your repair will last a lifetime.
After the repair is completed, the small holes in the concrete where the material was injected need to be filled. Unlike the 2 inch holes drilled for mudjacking, Leveled Concrete’s polyurethane system utilizes a much smaller, 5/8″ hole (about the size of a penny), and those holes are filled with a cementitious grout to match the surrounding concrete.
Mudjacking uses a mixture of sand and water infused with a small amount of Portland cement which helps the material solidify. The sand and water mixture is pumped through soda can size (1-5/8 inch) holes in the concrete using hydraulic pressure to lift the sunken concrete. This mixture is considered a structural fill and is very heavy, weighing an average of 100-110 lbs. per cubic foot of material. In areas of wet and unstable soils, mudjacking material can add additional, unwanted weight and water to an already wet and failing substrate. In the likely event that there is moisture present in the area where the slurry mixture is placed, over time that slurry mixture may have a tendency to absorb the moisture, causing it to weaken, break down, sluff off, and eventually become part of the failure. Mudjacking can be an effective solution, but in some cases may only be temporary.