Concrete slabs are often installed on poorly compacted fill dirt. Sub-surface erosion and shrinking soil, such as the clay found in Northeast Ohio are also contributing factors. Fill dirt is almost always placed closest to the sides of a new house and garage, after the foundation work is completed. Time constraints and completion deadlines make it difficult for a builder to take the time to properly compact this dirt. Natural settling often takes seven years or more in areas of clay soil.

What is Concrete Leveling?
Many people have replaced slabs that are in perfect condition only tilted or sunken. Demolition and replacement of concrete is expensive, messy and time consuming. The term Concrete Leveling has been used since the inception of the industry. Industrial terminology can be confusing. The purpose of the process is to eliminate “offsets” or “tripping hazards”, or to properly “pitch” (angle) the affected slabs. If concrete were actually level, water would not run off. A more accurate term would be, "Concrete Raising."

How does Concrete Leveling work?
The technology to lift concrete has been around for centuries. It is the same concept that your mechanic uses to raise your car on a hydraulic lift. Concrete Leveling is a process that involves pumping a dense material, under pressure, underneath a sunken concrete block, raising it into its original position.

1. A small (1 inch) hole is precisely drilled through the affected concrete block.

2. A highly dense, finely crushed limestone (sometimes combined with cement), is mixed with water in a “slurry” consistency and pumped into the holes. The material fills any “void” areas that have been created by water erosion or compaction. As it begins to flow under the slab, it exerts an equal pressure on every square inch of concrete that the pump produces. Thus, if the pump produces just 5 -10 pounds per square inch pressure, it can easily raise the slab.

3. Once the voids have been filled, the block will be pressurized and begin to rise. Through precise placement of the holes, and control of the amounts of material injected, the block will be carefully moved into the correct position. Common applications for Residential Concrete Leveling include: sidewalks, steps, patios, driveways, swimming pools, garage floors, and interior slabs. Concrete Leveling usually saves 50% to 75% over the cost of removal and replacement.

How long has Concrete Leveling been in existence?
Accounts of raising large cement slabs through the use of hydraulic pressure go back almost a century. Mudjacking or Slabjacking has been in common use for about 50 years. Refinement of the process to its current state occurred about 20 years ago when Grover Miller an inventor from Peninsula Ohio, began working on A-1’s patented Self-contained pumping truck, combined with a highly-dense crushed limestone material.

Generally in Mudjacking or Slabjacking a portable pump is carried to the location of the block to be raised. A hole of up to 3 inches in diameter is drilled into the block. Varying combinations of soil, sand, cement, or other materials, are mixed and then injected under the sunken concrete block, causing it to rise.

Problems associated with Mudjacking involve: containment of the mess caused by excess mud or material in the area to be raised; drilling of large holes that can weaken the block, and allow material to flow too quickly causing cracking of the slabs.

Modern Concrete Leveling techniques utilize smaller holes to avoid weakening the concrete slab, or raising the blocks too quickly. A highly dense crushed limestone is sometimes mixed with moderate amounts of cement, and can be pumped slowly and safely through hoses that are connected directly to the pumping truck.

What are the benefits of Concrete Leveling over replacement?
The cost of Leveling usually represents a savings of 50% over replacement.
The leveling process can be completed and ready for use in a matter of hours
Landscaping and adjacent areas are usually unaffected by our process.
Injection of our materials help to fill voids and stabilize low-density soils
Leveling maintains the uniform color of your concrete slabs.
Concrete Leveling reduces job time, energy utilization, and environmental problems associated with concrete demolition, and disposal.
No Municipal Building Permits required.

Can any concrete slab or block be raised or leveled?
Generally, Yes. However when large areas have crumbled or deteriorated, replacing the concrete may be the only option.

Our concrete appears to have “raised up”. Can Concrete Slabs be lowered?
Generally, no. However adjacent slabs can be raised to “match and even” thereby eliminating “offsets” or tripping hazards.

Our driveway is leaning toward the house, and water has appeared on our basement wall. Water is leaking into our basement. Can our cement be raised to direct water away from the house?
In many cases we are able to lift the driveway or patio blocks to allow the blocks to “pitch” away from the structure. This method combined with caulking or sealing of cracks and joints often improves problems associated with water seepage. Raising concrete blocks will not completely solve water problems if footing drains have failed, or other drainage problems exist.

My front steps have sunken, and there is a gap at the top. Can they be raised?
Generally yes. There are some isolated circumstances where steps cannot be raised. If the steps are made of materials other than solid concrete or they are in a deteriorated condition, they may not be able to be raised. It is best to have your A-1 representative examine the steps to provide you with a free quote or help advise you about your options for repair. It is important to note that the gap at the top and sides of the steps will usually not close. Most gaps can be sealed with polyurethane caulking to resist water penetration, and provide an acceptable appearance.

Tree roots have lifted my sidewalk. Can it be leveled?
When one or more blocks have raised, the surrounding blocks can be raised to “even” the offsets. This technique results in a gradual slope that will eliminate the “trip hazards." In some cases however, the tree roots lift the sidewalk too high to be properly evened.

What is a “Void”?
Voids are "pockets" of air or water beneath the concrete. They are created by erosion, poor compaction, or normal settling of clay or organic soils. These types of soils can cause big problems for buildings and concrete slabs. Concentrated loads, such as buildings or slabs can literally squeeze air and water from soils. When this happens, the soil sinks and the buildings or slabs follow closely behind. Since voids cannot be seen, filling them is often quoted on an hourly (Time and Materials) basis.

How long will concrete leveling or raising last?
Although every situation is unique, concrete usually sinks because of water erosion, compaction of soil underneath the slab, or movement on an incline. A-1’s process of filling with an extremely dense material dramatically improves the compaction of the underlying soil, however, some soils i.e. peat contain high levels of organic material and may be difficult to stabilize for long periods of time. Water erosion is probably the most critical issue. Improper drainage, broken or misaligned pipes or utilities, or surface cracks may allow water to “undermine” the soil under the slab. With proper drainage and sealing of cracks and missing expansion joints*, leveling can last indefinitely.

*Polyurethane caulking is highly recommended for most concrete applications.

How does Concrete Leveling compare in cost to other repair or replacement options?
Concrete Leveling usually saves 50% to 75% over the cost of removal and replacement.

Please bear in mind that if a partial replacement is done there will be a variation in color between the new and old pours. With concrete leveling, the continuity of color is maintained with the exception of the small 1” holes used to inject the material.

Some companies provide a “Grinding Service” for offsets or “trip hazards”. Grinding exposes the aggregate within the cement and results in an extremely noticeable difference in color. A-1 does offer limited grinding services primarily for commercial applications. Grinding can provide a cost-effective option to leveling, if appearance is not a major concern.

Will the holes used in leveling be a different color than our existing cement?
It is virtually impossible to match the color of existing concrete. A-1 uses high quality mortar mixed with the drilling material that we save from your existing concrete. Over time, Due to weathering, sun, and other environmental discolorations, our mortar will begin to blend with the existing concrete.

How do the costs of Concrete Leveling Companies compare?
In most cases the costs for Concrete Leveling, Mudjacking and Slabjacking are comparable. It is always our goal to quote a fair price for excellent work.

Please bear in mind that:

A-1 has Local Ownership with the support and expertise of a National Franchise
A-1 uses Smaller Holes resulting in a safer, cleaner process
Our specially designed 5 PSI pump exerts less stress on your concrete
A-1 has an exemplary record of honoring our warranties
A-1 is a fully insured contractor
A-1 uses State-Of-The-Art Equipment and Technology

Is Concrete Leveling a seasonal business?
Most of our work is done from April 1st through the end of November. Since we use a material that is mixed with water and pumped through hoses, our equipment is vulnerable to problems associated with freezing conditions. We do provide free estimates throughout the year.