Polyjacking vs Mudjacking Cost Sizer

The Overburden Dead Load Paradox

The most critical engineering failure mechanism in traditional mudjacking is the overburden dead load paradox. When a concrete slab drops, the soil beneath has already demonstrated that its allowable bearing capacity (typically 1,500 to 2,000 psf in compressible clays) was insufficient to support the 4-inch concrete slab (which weighs ~50 lbs/sq ft).

To lift the slab back up, mudjacking pumps cubic yards of wet portland cement and pulverized limestone. In a typical two-car driveway lift requiring 90 cubic feet of void fill, mudjacking pumps 9,900 lbs (nearly 5 TONS) of heavy mortar directly onto that exact failing soil. The dead weight of the repair material often exceeds the weight of the original concrete slab, accelerating secondary consolidation settlement within 24 to 36 months.

In contrast, polyurethane foam achieves high compressive strength (up to 100 PSI / 14,400 psf per ASTM D1621) while adding only 250 to 350 lbs of total weight to the same 90-cubic-foot void. It fills microscopic fissures, consolidates loose base gravel, and creates an impermeable hydrophobic barrier that seals out future runoff erosion.

Sizing & Dead Load Sensitivity Matrices