Void Filling/Pressure Grouting/Slab Jacking

Residential Services - Void Filling, Pressure Grouting, Slab Jacking #9

Mud Jacking and Slab Jacking

Mud jacking, also known as slab jacking, refer to a procedure used when a concrete slab or foundation sinks.  This sinking is typically caused by improper installation, shrinking soil or potentially sub-surface erosion.  A slab can be “floated” or jacked back to its original positioning by pumping in a mixture of cement, sand, topsoil and other adhesives under the slab using low pressure.  Strategically drilled holes are made in the slab and with the use of flexible hoses and portable pumps these holes are filled with this mixture.  The process can be accomplished in a few hours by lifting the slab using these methods.

Slab jacking is used to raise patios, garage floors, driveways, basement floors, walkways, pool decks and porches.  It can remove fill voids, pooling water and trip hazards.  As an alternative to replacement of uneven or sunken concrete, slap jacking can restore sunken areas to their original level. The procedure can be done on cracked areas such as in concrete paved floors and surfaces, sidewalks and steps and driveways.  It can not only bring the surface to grade but it can eliminate water problems as it fills in cavities under the concrete and it will divert the water away from the foundation.

This quick and easy process produces very little inconvenience or mess and allows for immediate use.  There is no waste with this process, unlike replacement which adds to landfill making this method environmentally a better choice. And quite often there is no noise from breaking up old concrete to remove it, no dust and no chunks of concrete.  The color of the concrete remains the same as the old areas are still in place.

As with any repair project, prior to planning a repair, one should always try and determine the reason for the distress in order to fix it properly.  Inspect windows, mortar joints in brick veneer moldings and trim boards.  If the weather has been unusually wet or dry it can cause problems in the way the soil behaves.  If there is a large problem to repair such as in the shifting of a commercial or residential building, piering can be used to lift the foundation to stabilize it. Piering uses mechanical jacks to lift a settled beam so that it is at grade level. This must be done very carefully so as not to cause any other damage.  It is held in place by a spread pier and footing.  This footing or pier is set well below the problematic area, deep into the soil so as not to be affected by moisture variations in the soil. It distributes the load evenly without any additional mass and is tied with steel supporting the foundation beam.

While mudjacking is a solution, it more than likely is not a permanent solution as it does not get below the affected area.  In certain instances, an alternative method such as helical or resistance piering is a more cost effective and more permanent solution to consider.  Regardless of the method used, it should be understood that the solution is not a DIY project and one should consult a professional foundation repair contractor  as these methods are beyond the scope that a homeowner should handle.