Uneven Concrete: Sidewalks, Driveways & Patio Slabs in Nashville, TN

Not every slab is a good candidate for lifting. Concrete that is severely cracked, crumbling or structurally damaged may need replacement. During an inspection, a specialist evaluates both the slab and the soil beneath it to determine whether lifting is appropriate. 

Concrete often settles unevenly because soil conditions vary beneath the same slab. One section may remain supported while another loses soil to settlement, erosion or poor compaction, which causes only part of the sidewalk, driveway or patio to sink. 

Polyurethane foam lifting is intended as a long-term repair because it fills voids and restores support beneath the slab. How long it lasts also depends on drainage, future soil movement and the condition of the concrete. Fixing water problems around the repaired area can help protect the supporting soil from additional erosion. 

It can, yes. If the soil beneath the concrete continues to settle, erode or change with moisture, the slab may continue to move. Water is particularly worth keeping an eye on. If it is working beneath the concrete, it can continue eroding the soil and open up larger voids beneath the slab. Drainage and soil conditions are worth considering when determining whether the problem is likely to progress. 

Cost depends on the size of the affected area, how far the concrete has settled, the condition of the slab and the repair method needed. That’s why there isn’t one set price for uneven concrete repair. A specialist can assess the concrete and the soil conditions and provide pricing based on the work your property actually needs. When the existing concrete can be lifted, the cost is usually lower than removing the old concrete and installing a completely new slab. 

Uneven concrete can create a trip hazard, especially on sidewalks, walkways, patios and steps. It doesn’t take a large raised edge to catch someone’s foot. It can also raise accessibility concerns and potential liability issues around frequently used areas of the property. If the concrete has noticeably shifted, it’s worth having the area evaluated to understand whether the movement is likely to continue. 

Yes. Uneven concrete can usually be leveled without replacement if the slab is still structurally sound. Polyurethane foam lifting fills voids under the concrete, restores support and raises the settled section back toward level. This can be a more affordable and less disruptive option than replacing the entire section. Replacement can be necessary when the concrete is severely cracked, damaged or otherwise unsuitable for lifting. An inspection can help determine which approach makes sense. 

Uneven concrete is most often caused by changes in the soil beneath the slab. Soil can settle or compress, water can wash it away, and moisture changes can cause some soils to expand and contract. Freeze-thaw cycles also contribute to movement. Poor soil compaction, drainage problems, heavy vehicle traffic and sometimes tree roots can also play a role. The concrete itself is often still in good, usable condition, the problem is that it’s lost some of the support it originally had underneath it.