Backfill → The placement of soil into a hole or against the perimeter of the foundation, sloped to drain away from the house
Clay soil → As the moisture content of clay soil increases, the soil swells and may “heave” the foundation upward. As the moisture content decreases, the clay soil shrinks and the foundation “settles”. This is not a problem if all the soil under the foundation swells or shrinks uniformly. This ideal situation only occurs if the homeowner practices proper moisture maintenance.
Cut and fill → Removal of excess existing soil (cut); Soil added to provide a level construction surface or desired grade(fill).
Elevations → Measurements taken by instruments such as the “Compu-level” or “Zip-level” to prepare an elevation survey of your foundation. The survey will document the current existing elevations of the foundation throughout the structure to aid in determining how level (or out of level) the foundation is and where the movement begins and ends.
French drain → A common drainage system, primarily used to prevent ground and surface water from penetrating or damaging a building’s foundation. A perforated pipe wrapped with geotextile filter cloth is installed in an excavated trench to intercept and divert water away from an area. The trench is lined with geotextile filter cloth and filled with washed gravel. Typically, a continuous gravel strip is left exposed along the surface of the drain. Sometimes a catch basin and discharge pump (sump pump) are required if the natural grade does not provide sufficient slope away from the site.
Jacking → A means of imposing a driving force on steel pier sections that are driven through heavy-duty steel foundation brackets, using hydraulic jacks to reach deep down to rock or other competent load-bearing strata.
Load bearing strata → A layer of rock or stiff soil that has the capacity to accept and dissipate the force imposed upon it
Grade beam → A reinforced concrete, load-bearing support around the perimeter of a structure.
Pier-and-beam → A foundation type that incorporates a “crawlspace” (usually at least 18 inches) between the soil and the raised wood floor system. Generally these foundations are supported by concrete piers or blocks founded on a spread type footing.
Plumbing leaks → Damage to plumbing pipes, either fresh water pipes or sewer lines, which causes water to accumulate under the foundation. These leaks can cause “upheaval” of the foundation and should be located and repaired as soon as possible. Usually of greater concern with slab foundations.
Refusal → The condition reached when a steel pier being driven by a hydraulic jack reaches an impenetrable bottom such as rock; when the effective energy of the jack is no longer sufficient to cause penetration.
Root barrier → A barrier material installed between the foundation and trees located within close proximity to the house to protect the foundation from tree roots migrating toward the moisture in the soil under the house. Large trees and shrubs close to the house may remove enough moisture from the soil under the foundation to cause settlement.
Settlement → The drop of some portion of the foundation below the original as-built grade.
Shimming → A process that is used in pier & beam foundations to make simple interior floor level adjustments. Commonly used wood shims can be replaced with high quality steel shims.
Slab-on-grade foundation → A concrete foundation that is supported entirely by the surface soils. The “slab” foundation is formed from a mold set into the ground. A sand cushion of several inches is laid and then the concrete is placed into the mold, leaving no space between the ground and the slab. It probably constitutes the majority of new residential construction in areas with high-clay soils.
Swale → A gently sloping ditch, dug to guide water away from the problem area.
Tuckpointing →A process used by skilled technicians to repair the mortar between bricks to restore the cosmetic appearance of your home’s exterior.
Underpinning → The process of providing additional support for an existing foundation system by installing piers to a subsurface strata that is deeper and more stable than the near surface soils that supports the existing foundation system. This is done to provide vertical support that is not present in the existing design.
Upheaval → The situation in which areas of the foundation (usually interior) are raised above the as-built position.
Void fill → The low pressure injection of a grout slurry to fill the space between the foundation and the soil, a “void” sometimes created when the house is lifted more than a few inches.