Why Does Concrete Settle?
The first thing to understand about concrete raising is why the concrete settled. It is common practice to blame the contractor who installed the concrete. Construction practices tend to focus on speed and contractors must install concrete around new buildings before the excavated ground has had a chance to settle. Other times, the excavating contractor does a poor job of compaction when backfilling, causing the concrete to settle soon after. Poor compaction is the most common reason for settling, however, even the most compacted areas will settle if insufficient drainage exists.
Natural Processes that Cause Settling
Concrete can also settle due to a variety of natural processes. The first is erosion, or the washing away of the dirt under a slab of concrete. Erosion occurs in any of the following ways: broken pipes under concrete can cause large voids to form. At corners of buildings concrete may wash out due to improperly placed downspouts. Insufficient or non-existent rain gutters cause excess rain to wash out dirt under and around driveway and patio slabs adjacent to a building. Water running downhill may wash through joints and erode the ground under slabs at the bottom of the hill. In an industrial setting, the vibration of machinery can causes fill material to compact and form voids beneath concrete slabs and machine bases. Animal and insect damage can remove soil supporting slabs, causing them to sink. In short, there are many ways that concrete can be undermined. In each case the hollow area must be filled with hydraulic grout in order to raise the slab. In addition, any drainage problems must be repaired soon after the concrete is raised to prevent it from happening again.
Another phenomenon that requires raising, but is not due to settling, is slab curl. Concrete slabs curl at the edges as the concrete cures, causing very small hollow areas to form at the edges. When heavy trucks pass over these areas, the concrete deflects cracking the concrete and causing edges to break off. This is easily repaired by pumping concrete slurry under each joint. This process causes minimal disruption and down time is held to a minimum.
The Best Solution…Concrete Lifting, or “Slabjacking”
ProLift Concrete Leveling lifts sunken concrete without the high cost and time lost in traditional tear-out and replacement. Most often, sunken concrete is easily repaired using a concrete slurry or hydraulic grout to fill the hollow areas under concrete. As the hollow areas are filled, the slab will lift and level.
Who Can Benefit From “Slabjacking”?
Factory Owners. Slabjacking saves the time and cost of tearing out and replacing concrete under valuable machinery. One-day service reduces down-time in factories.
City and State governments. Hydraulic grout or a special, lightweight polyurethane mix can lift concrete in bridge approaches, sidewalks and roadways.
Private Homeowners. Hydraulic grout can effectively lift porches, sidewalks, driveways, etc.
What if Concrete Lifting Isn’t an Option For Me?
We are fully licensed and insured general and engineering contractors. As such, we are able to offer services in removal and replacement of concrete, as well as flatwork, footings, foundations, landscaping and engineering if the traditional method of lifting concrete isn’t an option.