Foundation Repair Dictionary

The ratio of vertical drop over a given length. Maximum angular distortion defines the amount of foundation movement beyond which building materials such as sheetrock and brick or other building materials will crack. An angular distortion criterion of 1/500 is considered a safe limit that will not cause cracking to occur in the foundation or walls. 1/300 angular distortion from a foundation movement, on the other hand, is the limit that may cause cracking in walls and ceilings.

Defects that affect the appearance of a building due to foundation movement. Minor cracks typically less than .02 inches and .04 inches in plaster and masonry walls, respectively, are considered architectural damage.

The flatness of a foundation in construction "as-built." It is seldom recorded by the residential construction contractor so to ascertain how much the foundation is out of level, the foundation repair company must rely upon inferences in the structure.

A stable rock beneath deposits of soil. In the Kansas City area, we aim to drive foundation pilings to bedrock to provide the most robust support.

Soil with a high concentration of montmorillonite, a mineral with a high capacity to swell in the presence of water. The soil swell capacity may range from 4 inches to as much as 2 feet.

A root barrier material that stops the intrusion of roots under the house while allowing the free movement of water. It consists of a geotextile fabric impregnated with a chemical. Typically, it has a lifespan of 15 years. Plastic root barriers may fail in 5-10, while heavy rubber root barriers can be effective for 30 years.

Metal strips that hold the brick veneer to wood or metal wall studs are called brick ties. Foundation movement can exert enough force to cause brick ties to fail, and the ties to separate from the brick or the wall shifting the veneer outward. Foundation repair cannot correct brick tie failure. Instead, the brick must be removed and replaced following a foundation repair.

Before foundation repair work commences, a building permit must be issued. For that, the contractor must be registered, the repair plan must be approved, and completion of the work must be done in compliance with the repair plan certified in writing by a Registered Professional Engineer.

Given by the Foundation Repair Association, this title certifies trained professionals who fulfill a minimum level of experience and pass a proficiency exam encompassing a wide range of foundation repair issues. Once certified, the professional must annually complete a specified level of continuing education in order to maintain the certification.

It happens when a foundation fails by even a small amount. Being a tall structure, a chimney can twist or even separate from the house. Its height magnifies the effects of even the slightest of movements.

They are the main culprit in most of our foundation repair problems. The soil in the Kansas City area is described as clay, although only a small percentage is clay in its composition. This soil is notorious for expanding in the presence of water, losing its ability to bond. Soil expansion must be considered when designing foundations on clay.

Water can cause clay soil to expand and swell from a few inches to up to two feet. Uneven soil swell can cause the foundation to be subjected to bending stress. When the swell under a pier and beam foundation is uneven, the piers can move upward by different amounts, making your wooden floors uneven.

The volume of compressible soils decreases when it is subject to loading. Examples of highly compressible soil types include clay, loose sand, and uncompacted fill. To provide adequate support for a residential foundation, compressible soils must be compacted.

A concrete cylinder is one of the products utilized in foundation underpinning. It is made of precast concrete typically 6 inches in diameter and 10-12 inches in length. The concrete is rated at 5000 PSI or greater after 30 days of curing. The maximum force available to drive a concrete cylinder piling into the ground is the weight of the structure at that particular location.

A test to determine the extent of compression of soil. In this test, a soil sample is placed in a container and pressed between porous plates to measure the extent of its compressibility.

A destructive test used to measure the thickness and check for signs of deterioration in a cut out concrete sample. A deteriorated concrete in a foundation may indicate the foundation cannot be adequately repaired using foundation underpinning and may need replacement.

They are installed on both sides of a crack, periodically measuring their distance to determine the amount of opening or closing of a crack.

A process of cutting off the hilltops and using the fill materials for the valleys. The problem with cut and fill is that if the cut area is of clay, it is prone to expand as it is exposed to more surface moisture.

In areas like Kansas City, it typically ranges from eight to ten feet. Piers or pilings should, therefore, be driven below this depth or until they rest upon a rock like strata.

Proper drainage is necessary to prevent water pooling near the foundation and avoid foundation failure. Soil should be sloped away from the foundation at least 1 inch per foot for a distance of 8 feet.

The expansive movement of clay soil in places like Kansas City. Clay soil swells and shrinks with the increase and decrease in moisture content.

A term used to describe post-tension or slab-on-grade slabs. It infers that the slab will float upon the load-bearing soil. In the past, floating slabs did not have beams and footings. They were added later to enhance resistance to bending and distorting.

Part of pier and beam houses, that are paced every 16 to 24 inches to provide the base for materials such as particleboard or plywood.

A diagram that contains contour lines for a foundation developed similarly to depict the contour of mountains. It aids the foundation evaluator in assessing evidence or trends of foundation movement.

Properly designed drainage slopes away from the house in the range of 1% over a 10 feet distance from the foundation. It ensures that no water accumulates near the foundation.

A process of measuring the foundation elevation at numerous points before foundation repair. A contour diagram is then created from these measurements to show developments in floor elevation changes. The foundation inspector uses the measurements and other structural signs to determine the extent and level of foundation movement.

Foundation failure is open to many interpretations. It may describe problems from foundation tilting or differential movement across the foundation. Warranty companies may define it as foundation failure when the foundation fails to support the house securely or when the structure is no longer habitable. There is no available universal agreement on foundation failure.

Heaving occurs in expansive soil or rock when there is an increase in water content in the soil. It is the upward movement of a structure or foundation caused by expansive soil or rock or frost when water forms ice layers in the soil.

A problem that describes when a foundation center has heaved upward, or the foundation perimeter has dropped downward.

A phrase that generally describes the process of shimming a pier and beam foundation or underpinning a slab foundation. While foundation companies will attempt to level a foundation, no reputable contractor can claim to be able to do it to perfect flatness. They have no control over the tolerances the original contractor used and the effect of the natural aging process of concrete as well as the aging and warping of wood used in the foundation.

A deep column foundation repair system created by boring a hole and filling it with steel-reinforced concrete. The terms pier and piling are often used interchangeably by laypersons and contractors when referring to the methods of underpinning a failed foundation.

A deep column system of foundation repair that consists of pushing columns like members such as steel and precast concrete into the ground. Also called pier, piling refers to the members used to underpin and repair a failed foundation.

Freshwater or sewage line can trigger a plumbing leak. Leaks even when minor can cause expansive soils to swell and lift an area of the foundation. A major plumbing leak, on the other hand, can lead to soil erosion and foundation slumping. In some instances, a foundation plumbing leak may be the cause of foundation failure, or may also be the effect of foundation failure.

A license for foundation repair work is not required in Kansas City. Instead, a building permit issued to companies registered with the municipal agency is needed.

A material which prevents roots from intruding under a foundation. Roots typically seek out areas under foundations for moisture, especially in hot climates. Expansive clay soil will contract, and the foundation can fail as the roots absorb moisture. The root barrier material may be made of plastic, metal, bitumen, or chemical. The root barrier consists of a porous cloth impregnated with chemicals allowing the free movement of water.

The foundation is said to have sagged when the load-bearing soil fails to provide adequate support.

Slab cracks may be minor cosmetic cracks due to normal drying, or hydration or visible slab separation, or changes in elevation of the slab. The latter case requires immediate attention and repair action.

When the foundation failure compromises the stability of a building, the damage is structural.

A foundation that retains its flatness but is no longer level is described to have tilted. Cracks in walls are not necessarily caused by a tilted foundation but by angular distortion or bending of the foundation.

The process of digging tunnels under the foundation to provide places for pier installation. Tunneling is opted to preserve expensive floor coverings. The process does not, in any way, compromise the quality of underpinning installation.

A generic term to describe the placement of pilings or piers under a structure to provide support to a foundation.

A crack that often occurs at the corner of a foundation resulting from the force exerted by brick veneer upon the slab. It is caused by a difference in the thermal coefficient of expansion of brick and concrete. A foundation wedge crack is not considered a structural failure.

The effects of foundation movement that cause doors to jam, walls to tilt, and extensive cracking to occur.

Also called a screw pile, a helical pier consists of a round or rectangular shaft with a screw-shaped plate. It is rotationally screwed into the ground. Atop it is placed a bracket that supports the foundation. Helical piers are typically driven to a specified minimum depth and rotational torque limit that are consistent with the soil type. These piers consistently achieve greater penetration depth than their concrete pier counterparts.

A structurally supporting cross member in the house’s foundation. Building code defines the required beam thickness and width and the load needed to support it.

The maximum load or weight that the soil can withstand before it compresses. An increase in moisture level diminishes the load-bearing capacity of expansive clay soil.

The process of injecting a slurry of soil and cement under pressure through holes in a foundation to lift the slab. An inadequately controlled mudjacking may over lift a foundation.

A wooden framed house where the beams, the main structural members, sit atop concrete pillars or wooden posts called piers. The piers rest on the surface of the soil and usually are buried to a depth of two feet.

A leak test performed after a foundation repair.

Wooden posts embedded in the ground may be used to support the foundation of the pier and beam house.

Pre-cast concrete cylinders used in the foundation repair method. They are pressed as deeply as practical into the ground, and the depth is dependent upon the soil type, weight of the house, and the soil moisture content.

Refusal is the inability to press the piling any deeper during pressed piling installation. This depth to refusal is dependent upon surface friction of the piling, piling driving pressure, end bearing surface area of the piling, soil composition, soil density, and soil moisture content.

A failing foundation may cause, among others, the roof beams and joists to move. Failure in the foundation may cause joists, beams, and roofing to physically separate.

The foundation is subjected to seasonal foundation movement as clay soil expands in the wet spring, and shrinks in the hot summer.

Spacers used to achieve optimal elevation in pier and beam foundations. Wooden shims in pier and beam foundations may compress. That is why steel shims are the best choice when shimming.

The process of drilling a hole and removing a soil sample to examine the characteristics of a soil. Borings are essential to have an understanding of underlying soil type, moisture, and compaction to be able to design a proper foundation.

A mechanical method of increasing the density of the soil to improve its ability to support a foundation. It consists of compressing clay soils in layers of 4 inches or less.

A gradually slow outward and downward movement of soil along a slope. It is a common cause of foundation failure on hillsides. It can also occur due to inadequate retaining wall support.

A slow process of settling foundation as a result of soil compacting, collapsing or compressing. A settling foundation is often repaired with the installation of piers or pilings.

The shear stress that soil or rock can sustain. A foundation may fail when shear failure occurs, and the soil is no longer able to provide adequate foundation support.

A slope failure happens when a slip along a surface occurs. A most severe form of slope failure is a landslide.

They typically provide the best long term foundation repair for soil conditions such as what we have in the Kansas City area. They are driven to rock.

Similar to mudjacking, expansive urethane foam is injected into drilled holes in a foundation floor. As the urethane foam expands, it lifts the foundation.

A brick wall that slips along the base of a foundation. This is caused by repeated sag and upheaval of a foundation.