Whether its mudjacking, or polyurethane foam injection (polyjacking), both are designed to accomplish the same results, which is to fill in voids and raise sunken concrete.
Mudjacking uses a grout-based material, fused with cement. The process requires a 1″ diameter hole, which is drilled through the slab, which the grout is then hydraulically pumped under the slab, resulting in the voids filling in, causing the slab to be lifted. The material for this process weighs approximately 100 lbs per cubic foot.
Mudjacking involves:
- Drilling a series of 1″ diameter holes
- Hydraulically pumping a grout-based material underneath the slab
- May require more holes than polyjacking would require, to properly fill in voids. The injected grout takes approximately 24 hours to cure
- Drilled holes are sealed with a non-shrink grout
- Material weighs approximately 100 lbs per cu. ft.
Polyjacking uses a two part expanding polymer foam. The process to raise the concrete by foam injection requires a small hole, approximately 5/8” in diameter, drilled through the slab. The polyurethane is then injected under the slab, which through its expansion stage, may interact with any loose soils, filling in all the voided areas, resulting in raising the sunken concrete. The material for this process is very dense, and only weighs approximately 2 lbs per cubic foot.
Polyjacking involves:
- Seeks out weak soils, and during expansion, creates a strong, dense, sub-base
- The material will take the path of least resistance, and will fill in all voided areas
- Will retain its cured shape and form, reducing the possibility of forming new voids or further settlement
- Completely cures within 15 minutes
- Very strong, dense, and lightweight
- Requires much smaller and fewer holes