The process of lifting and leveling concrete involves injecting a compound beneath the slab to fill voids and create enough pressure to raise it back to the desired level. Here's a breakdown of the process:
1. Assessment and Planning:
- Before any work begins, a thorough inspection is crucial to identify the extent of the settlement, the cause (e.g., soil erosion, poor compaction), and any underlying issues.
- A plan is developed to determine the strategic locations for drilling injection holes. These locations are critical for even lifting and leveling.
2. Drilling Injection Holes:
- Small holes are drilled through the concrete slab at the pre-determined locations. These holes act as access points for injecting the leveling compound.
3. Injection of Leveling Compound:
- A specialized leveling compound is pumped through the drilled holes. Common materials include:
- Polyurethane Foam: A lightweight, expanding foam that is often preferred for its fast curing time and ability to fill large voids.
- Grout (Cement-based or Chemical): A mixture of cement, sand, and water (or chemical additives) that is pumped under pressure to fill voids and stabilize the slab.
- The compound fills any voids beneath the concrete slab, providing support. As more material is injected, it creates backpressure, causing the concrete to rise. Skilled technicians monitor the lifting process to ensure even and controlled movement.
4. Monitoring and Adjustment:
- Throughout the injection process, the concrete slab is carefully monitored using levels and other measuring tools.
- Adjustments are made to the injection rate and pressure to ensure the slab is lifted evenly and to the correct height.
5. Patching the Holes:
- Once the concrete is properly leveled, the injection holes are patched with a concrete mixture that matches the existing surface.
6. Finishing:
- The patched areas are smoothed and finished to blend in with the surrounding concrete.
Summary:
Concrete lifting and leveling is a process that involves strategic drilling, injecting a leveling compound to fill voids and raise the slab, monitoring the process, and patching the holes. It's a cost-effective alternative to completely replacing sunken or uneven concrete.
