What is Polyurethane concrete raising?
Polyurethane concrete raising or mudjacking is a newer method of lifting and leveling concrete. Various marketers behind polyurethane foam ‘mudjacking’ pitch it as a reliable, cost-effective solution to raising, and leveling concrete such as patios, driveways and even foundations.
A 5/8″ hole is drilled through the slab and into the subgrade. For most; a tapered delivery port is placed into the 5/8″ hole, and the injection gun is then connected, and then delivers the polyurethane material through the port.
As the polyurethane passes through the port, expansion of the material starts. Within about 10 to 15 seconds the polyurethane foam will fully expand which allows the technician to monitor the rising of the slab, and prevent overriding.
Polyurethane concrete raising is becoming significantly more popular over traditional mudjacking.
Polyurethane Concrete Raising Vs. Mud Slurry Mudjacking
As of recent, the effectiveness of Polyurethane mudjacking has been challenged. Dr. James Warner, P.E., Author of the Practical Handbook of Grouting: Soil; Rock; and Structures.N.p.: n.p.,2004. Print. wrote, “Because the injected material [foam] reacts and reaches its maximum volume in increments shortly following injection, significant voids remain after treatment. This was found to be the case when a bridge approach slab near the Denver airport that had been so treated [with foam] continued to settle and was subsequently removed.”
Additional concerns to polyurethane mudjacking include various health and environmental concerns. I recently published an article on 303News titled, WARNING: The Alleged Dangers of Some Polyurethanes (FOAM) where I link to a manufactures safety data sheet. The safety data sheet is especially alarming. You can view their hazard statement below.
Consumers should be especially cautious when considering applying polyurethane foam vs an organic base, mud slurry.
Additional Resources:
- Is Polyurethane Foam Toxic?
- Polyurethane Foam Health Effects
- Polyurethane Foam Dangers Health Risks
- Google Search: Polyurethane Foam Toxic
If you hire a polyurethane foam concrete leveling company, be sure to ask for their safety data sheet. When in doubt, it’s best for the environment to use the organic based material.