Concrete Lifting Systems

Mudjacking

• Mudjacking is the more common lifting system. The methods behind it are very simple. Holes are drilled into the part of the concrete that is sagging. Usually, depending on the severity of the sinking, two or three holes are sufficient. Through this hole, a mortar compound made of portland cement, sand, gravel and water is pumped under the concrete. This then lifts the slab that is sinking.

Sandjacking

• Sandjacking is less commonly employed because generally a sandjacker must have access to both sides of the sinking slab, and that is rarely the case in a house. For jobs like uneven sidewalks, sandjacking is becoming the option of choice. The process does not use drill holes in the concrete. Instead, braces are driven into the ground on one side of the slab. The slab is then jacked up. Sand and gravel are sprayed out of a high pressure hose underneath the slab. The process is repeated on the other side until the piece is even.

Foam Lifting

• In some cases, the mudjacker uses a compound of a strong, rising foam made from a polyurethane compound. This foam does more than just push the slab. First, it penetrates deep into the ground, filling in every void underneath, no matter how small. This gives added support to the slab. Next, it expands once it is pumped, pushing the slab to its even position. This saves time and money because less of the substance is required for the same lift. The foam then solidifies into a mortar-like hardness, supporting the slab.

Sandjacking vs. Mudjacking

• Sandjacking is often the better option. This is because the sand goes under the slab dry, meaning that there is no evaporation later on. In addition, the sand is sprayed evenly, while the pumped mortar usually stays in one spot, creating a “pyramid” effect. Sand is easier to work with, too, and it does not settle. Mudjacking foam can solve some of these problems because it stabilizes as well as lifts. Because the sandjacking system is normally only used when access to the sides of the slab are available, however, it can only be used in special cases.