Foundation Repair Dictionary
The purpose of the Foundation Repair Dictionary is to provide information for the homeowner regarding terms and definitions unique to the foundation repair industry. It has been prepared drawing upon over 40 years of foundation repair experience by the team at Granite Foundation Repair, Inc. This is for the lay person and is not to be construed as providing strict engineering definitions of foundation repair terminology. For many readers, the definitions herein are enlightening and help to explain causes of foundation problems and foundation repair methods.
- Angular Distortion of Foundation
- Architectural Damage
- As Built
- Bedrock
- Bentonite
- Bio-Barrier
- Brick Tie Failure
- Building Permit
- Certified Foundation Repair Specialist
- Chimney Rotation
- Clay Soil
- Clay Soil Swell
- Compressible Soil
- Concrete Cylinder
- Consolidation Test
- Coring of Foundation
- Crack pin
- Cut and Fill
- Depth of Minimal Seasonal Moisture Variation
- DiG TESS
- Drainage
- Expansive Soil Movement
- Floating Slab
- Floor Joist
- Foundation Contour Diagram
- Foundation Drainage
- Foundation Elevation Measurements
- Foundation Failure
- Foundation Heave
- Foundation Hogging
- Foundation Leveling
- Foundation Pier
- Foundation Piling
- Foundation Plumbing Leak
- Foundation Repair License
- Foundation Root Barrier
- Foundation Sag
- Foundation Slab Cracks
- Foundation Structural Damage
- Foundation Tilt, Tilting
- Foundation Tunneling
- Foundation Underpinning
- Foundation Void Box
- Foundation Wedge Crack
- Functional Foundation Damage
- Helical Steel Pier
- House Beam
- Lateral Expansive Soil Movement
- Load Bearing Capacity
- Mudjack
- Pad and Block Pier
- Pier and Beam House
- Plumbing Failure, Plumbing Leak
- Plumbing Test
- Post for Pier and Beam
- Post Tension Slab
- Pressed Concreted Pilings
- Pushing Pilings or Piers to Refusal
- Refusal
- Registered Professional Engineer
- Roof Joist
- Roof Movement
- Roof Rafter
- Sagging Foundation
- Seasonal Foundation Movement
- Seasonal Moisture
- Shim, Foundation Shimming
- Slab on Grade Foundation
- Soaker Hose
- Soil Boring
- Soil Compaction
- Soil Consolidation
- Soil Creep
- Soil Cut / Fill
- Soil Plastic Limit
- Soil Sample
- Soil Settlement under Foundation
- Soil Shear strength
- Soil Slope Failure
- Soil Stabilization
- Soil Swell
- Steel Pier / Piling
- Texas Residential Construction Commission (TRCC)
- Urethane Injection
- Vertical Expansive Soil Movement
- Void
- Void Fill
- Walking Brick
Angular Distortion of Foundation – A ratio of vertical drop over length. Maximum angular distortion is used to define the amount of foundation movement beyond which brick, sheet rock, or other building materials will crack. Angular distortion criteria of 1/500 is a safe limit where cracking will not occur in the foundation or walls. Foundation movement causing an angular distortion of 1/300 is the limit where cracking may occur in walls and ceilings.
Back to Top
Architectural Damage – Foundation movement that affects the appearance of a building. Minor cracks in plaster are typically less than .02 inches and minor cracks in masonry walls are typically less than .04 inches.
Back to Top
As Built – In residential construction, the “as built” flatness of a foundation is seldom recorded. Therefore, a foundation repair company must rely upon inferences in the structure to determine how much the foundation is out of level.
Back to Top
Bedrock – A relatively undisturbed rock beneath deposits of soil or at the top. Foundation pilings driven to bedrock provide the best support. In the Dallas Fort Worth area, it is practical to drive pilings to bedrock, while in Houston bedrock may be at an impractical depth of 900 feet.
Back to Top
Bentonite – A soil that has a high concentration of the mineral montmorillonite. This mineral characteristically has a high capacity to swell when water is added. In the DFW area, swell capacity may range from 4 inches to 2 feet.
Bio-Barrier – A root barrier material made of a geotextile fabric impregnated with a chemical that stops the intrusion of roots, while allowing the free movement of water. A bio-barrier has a typical life of 15 years. Plastic root barriers may fail in 5-10 years due to the force that roots exert upon the material. Heavy rubber root barriers can last 30 years.
Back to Top
Brick Tie Failure – Brick ties are metal strips which hold the brick veneer to wood or metal wall studs. When the ties separate from the brick or the wall, the veneer can shift outward. Foundation movement can exert sufficient force to cause brick ties to fail. Foundation repair will not correct brick tie failure. Following foundation repair, a wall with brick tie failure must have the brick removed and reinstalled.
Building Permit – Most Texas municipalities require the issuance of a permit prior to foundation repair. Permit fees may be as high as 1.2 percent of the cost of the work. For the issuance of a foundation repair permit: the contractor must be registered, the repair plan must be approved by a Registered Professional Engineer, and completion of work in compliance with the plan must be certified in writing by the Professional Engineer.
Back to Top
Certified Foundation Repair Specialist – The Foundation Repair Association confers this title upon trained professionals who meet a minimum level of experience and have passed a proficiency exam covering a broad range of foundation repair issues. To maintain certification the person must annually achieve a specified level of continuing education.
Back to Top
Chimney Rotation – When a foundation fails by even a small amount, a tall chimney can twist or separate from the house. This is because a small movement in the foundation is magnified by the height of the chimney.
Back to Top
Clay Soil – Clay soils are the root cause of our foundation repair problems. Soils in Texas and particularly the Dallas Fort Worth area are called clay even though they have only a small percentage of clay in the soil. Clay soils expand in the presence of water. Due to the flat nature of clay particles, when sufficient water content is attained, clay particles lose their ability to bond. We think of this as the muddy and slippery state of clay. This is contrasted with sandy soils, whose round particles are unaffected by moisture. Foundations on clay soil must be designed to allow for the clay soil expansion.
Back to Top
Clay Soil Swell – in the Dallas Fort Worth area, adding water to dry clay soil may cause it to swell or expand upward in the range of 4 inches to two feet. When the soil swell is uneven under a slab foundation, the foundation will be subjected to bending stresses. When the soil swell is uneven under a pier and beam foundation, the piers will move upward by different amounts, leading to uneven wooden floors.
Back to Top
Compressible Soil – Soil whose volume decreases when subject to loading. Highly compressible soil types include clay, uncompacted fill, and loose sand. A compressible soil must be compacted to provide adequate support for a residential foundation.
Back to Top
Concrete Cylinder – The concrete cylinder is one of the products used for foundation underpinning in Texas. Pre-cast concrete cylinder is typically 6 inches in diameter and 10-12 inches in length. The concrete should be rated at 5000 PSI or greater after 30 days of cure. To facilitate driving of concrete cylinders into the dry ground, the contractor may water inject the soil. The maximum force available to drive a concrete cylinder piling into the ground is the weight of the structure at that location. Weight is greater on inside corners of a house than on outside corners, so it is normal for concrete cylinders to be driven less deep on outside corners.
Back to Top
Consolidation Test – A soil sample is placed in a container and pressed between porous plates to determine the extent of compression.
Back to Top
Coring of Foundation – A destructive test performed by cutting out a sample of concrete. Used to measure thickness and check for signs of deterioration. Deteriorated concrete in a foundation may mean that the foundation cannot be adequately repaired using foundation underpinning. Deteriorated concrete may require replacement. A less satisfactory repair method is to mudjack a weak concrete foundation.
Back to Top
Crack pin – By installation of pins on both sides of a crack, periodic measuring of distance is used to determine the amount of opening or closing of a crack.
Back to Top
Cut and Fill – During site preparation, a developer will have hill tops cut off, and use the fill material for the valleys. The difficulties with cut and fill are that the cut area is of clay soil is exposed to more surface moisture, and tends to expand, while the fill area is seldom adequately compacted due to the difficult nature of compacting clay, and thus the fill area consolidates with time.
Back to Top
Depth of Minimal Seasonal Moisture Variation – In the Dallas Fort Worth area, this is typically eight to ten feet. Piers or pilings should either penetrate below this depth or rest upon a rock like strata.
Back to Top
DiG TESS – A non-profit corporation in Texas to promote excavation safety. Maintains a call center and personnel who mark buried line locations of member companies. Line location aids in avoiding cutting buried electrical cables, fiber optic cables, and gas lines. Texas Law mandates a 2 working day notice by the contractor to a Dig TESS call center to allow time for site marking before excavation can begin.
Back to Top
Drainage – Proper drainage is required to prevent foundation failure. Soil should slope away from the foundation in the range of 1 inch per foot for a distance of 8 feet. Drainage should prevent water pooling near the foundation.
Back to Top
Expansive Soil Movement – In Texas expansive clay soils swell as moisture content increases and shrink as moisture content decreases.
Back to Top
Floating Slab – A term given to slab-on-grade or post tension slabs inferring that the slab will float upon the load bearing soil. Early floating slabs did not have beams and footings, which were later added to enhance resistance to bending and distorting.
Back to Top
Floor Joist – In pier and beam houses, floor joists are spaced every 16 to 24 inches and provide the base for materials such as plywood or particle board.
Back to Top
Foundation Contour Diagram – Contour lines for a foundation are developed similarly to that of mountains. A contour diagram aids the foundation evaluator in assessing trends and evidence of foundation movement.
Back to Top
Foundation Drainage – Proper drainage is defined as a slope in the range of 1% over a distance of 10 feet from the foundation, thus assuring that water does not accumulate near the foundation.
Back to Top
Foundation Elevation Measurements – Prior to foundation repair, the foundation elevation is measured at numerous points. From these measurements a foundation repair specialist can create a contour diagram, which will show trends in floor elevation changes. The elevation measurements are relative and not absolute. A foundation inspector cannot rely upon the exact elevation measurements as the house was not built flat. The inspector uses these measurements along with other structural signs to determine the level and extent of foundation movement. Elevation measurements are typically only valid for the date of the measurement, and due to equipment sensitivity to temperature and cable stress, may be off by as much as +/- 0.3 inches.
Back to Top
Foundation Failure – Foundation failure may be either due to foundation tilt or to differential movement across the foundation. Home owner warranty companies may define foundation failure as when the structure is no longer habitable, or when the foundation fails to support the walls and roof in a safe manner. Defining foundation failure has been the objective of many court room dramas. There is no universal agreement on foundation failure.
Back to Top
Foundation Heave – The upward movement of a structure or foundation caused by frost or expansive soil or rock. Frost heave occurs when water forms ice layers in the soil. Expansive soil or rock heave occurs when there is an increase in water content in the soil.
Back to Top
Foundation Hogging – Describes when either a foundation center has heaved upward, or the foundation perimeter has dropped downward.
Back to Top
Foundation Leveling – A catchall phrase which generally describes the process of underpinning a slab foundation or shimming a pier and beam foundation. No reputable foundation company will claim to level a foundation for two reasons: 1) the foundation may have been built to a tolerance of +/-.75 inches or more, 2) the aging process of concrete and wood may preclude lifting the foundation to an approximation of its “as built” flatness. The wooden structural members are notorious for taking a permanent warp and may not adequately respond to foundation lifting. This is another reason why foundation repair should not be delayed.
Back to Top
Foundation Pier – 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 lay persons and contractors when referring to the methods of underpinning a failed foundation.
Back to Top
Foundation Piling – A deep column foundation repair system created by pushing column like members such as pre-cast concrete or steel into the ground. The terms pier and piling are often used interchangeably by lay persons and contractors when referring to the members used to underpin and repair a failed foundation.
Back to Top
Foundation Plumbing Leak – A plumbing leak may occur either in a fresh water or sewage line. In expansive soils, a minor leak can cause the soil to swell and lift an area of a foundation. A major freshwater plumbing leak can lead to soil erosion and foundation slumping. A minor sewer leak will over time also cause soil erosion and foundation slumping. A foundation plumbing leak may be the cause of foundation failure, or may be caused by the failure of a foundation.
Back to Top
Foundation Repair License -Foundation repair work is not licensed in Texas. Foundation repair work requires often requires a building permit, which requires that the contractor be registered with a municipal agency. Contractors who advertise that they are licensed are not licensed in foundation repair.
Back to Top
Foundation Root Barrier – A material which stops the intrusion of roots under a foundation. Root barrier material may be plastic, bituminous, metallic or chemical. In hot climates, roots seek out areas under foundations for moisture. As the roots absorb moisture, an expansive clay soil will contract, and the foundation can fail. A chemical root barrier consists of a porous cloth impregnated with chemicals that allows the free movement of water.
Back to Top
Foundation Sag – When the load bearing soil fails to provide adequate support, the dropping foundation is said to have sagged.
Back to Top
Foundation Slab Cracks – There are a couple of definitions of slab cracks. Due to normal drying, or hydration, a concrete slab will develop minor cracks, normally termed cosmetic cracks. Cracks which show visible slab separation, or changes in elevation of the slab merit immediate foundation examination and repair.
Back to Top
Foundation Structural Damage – When foundation failure imperils the stability of a building, the damage is clearly structural.
Back to Top
Foundation Tilt, Tilting – A foundation that is no longer level, but retains its flatness, is said to have tilted. A tilted foundation does not always cause cracks in walls. Cracks in walls are caused by angular distortion or bending of the foundation. The former government body, the Texas Residential Construction Commission (TRCC) defined unacceptable tilt as: The slab shall not deflect after construction in a tilting mode in excess of one percent from the original construction elevations resulting in actual observable physical damage to the components of the home. In plain English, TRCC allowed a maximum of 1 percent tilt in an 80 foot span. That is a whopping 9 inches. Even 4-6 inches of foundation tilt in an 80 foot span is unacceptable to the average homeowner. Remedial repair for foundation tilt is underpinning a majority of the foundation. This may help to explain why the TRCC was phased out in Texas.
Back to Top
Foundation Tunneling – When it is impractical to break though a slab to install underpinning, tunnels may be dug under the foundation to provide places for pier installation. Tunneling may be chosen to preserve expensive floor coverings. Tunneling does not compromise the quality of underpinning installation.
Back to Top
Foundation Underpinning – The placement of piers or pilings under a structure to provide support to a foundation. Foundation underpinning is a generic term for many forms of foundation repair.
Back to Top
Foundation Void Box – Used in foundation construction in areas with expansive clay soil. A box made of a slowly dissolving, water soluble material. Void boxes are placed on the ground prior to pouring of the concrete slab. This method creates an air space or void between the underside of the foundation floor and the expansive soil. A void box may be used in conjunction with poured piers to create the 21st century concrete version of a pier and beam house.
Back to Top
Foundation Wedge Crack – Often occurs at the corner of a foundation. Due to the force exerted by brick veneer upon the slab caused by a difference in the thermal coefficient of expansion of brick and concrete, a wedge breaks off the corner. A wedge crack is not normally considered to be a structural failure.
Back to Top
Functional Foundation Damage – Foundation movement that affects the utility of a building such as jammed doors, extensive cracking and the tilting of walls or floors.
Back to Top
Helical Steel Pier – Also referred to as a screw pile. A helical pier consists of a round or rectangular shaft with a screw shaped plate or multiple plates. The helical pier is rotationally screwed into the ground and atop it is placed a bracket which supports the foundation. Helical piers are chosen for foundation repair when it is not practical to use the weight of the structure during the driving process. Typically helical piers are driven to a specified minimum depth and rotational torque limit, consistent with the soil type. Helical piers consistently achieve greater penetration dept than concrete piers. Greater depth puts the underpinning system below the zone of seasonal moisture change.
Back to Top
House Beam – A beam is a structurally supporting cross member in the foundation of a house. Early concrete slab foundations had only shallow perimeter beams or no beams. In the Dallas Fort Worth area concrete slab foundations today are constructed with perimeter beams up to 36 inches deep and interior beams 12 to 24 inches deep spaced every 8-10 feet, running in both the x and y directions. Beam thickness and width are determined by building code and the load needed to support, such as a two story house. In Pier and Beam construction, wooden beams support the perimeter and are typically spaced longitudinally under the structure every 4 to 6 feet apart. Wooden beams are typically constructed of two 2x12s sistered / nailed together.
Back to Top
Lateral Expansive Soil Movement – Evidenced by retainer wall failure.
License for Foundation Repair – The State of Texas does not license foundation repair. Cities may require that a permit be issued for foundation repair. Cities require that a contractor be registered to obtain a foundation repair permit. Any company which states a license number in its advertising is misleading the customer, as the license is for some other line of work than foundation repair. Trades such as remodeling, plumbing and electrical are licensed by the State of Texas.
Back to Top
Load Bearing Capacity – The maximum weight or load which soil can withstand before it compresses. Expansive clay soil load bearing capacity is diminished by an increase in moisture level.
Back to Top
Mudjack – A slurry of soil and cement is injected under pressure through holes in a foundation in order to lift the slab. If mudjacking is not adequately controlled, it is possible to permanently over lift a foundation.
Back to Top
Pad and Block Pier – A method of supporting or underpinning a pier and beam house. The pad and block pier typically consists of a 2 foot square of concrete on the surface of the ground, topped with sufficient cement blocks to attain the desired floor height. The stability of the pad is dependent upon the ground beneath it. Clay soil must be adequately compacted, and free of moisture to provide adequate stability for the pad and block method of foundation support.
Back to Top
Pier and Beam House – Consists of a wooden framed house with or without brick veneer, whose main structural members, the beams, sit atop wooden posts or concrete pillars, which are referred to as piers. The piers typically rest on the surface of the soil or may be buried to a depth of two feet. The house is leveled by placing wooden or steel shims between the piers and the beams. The piers and beams are not nailed to one another. Some structures may be augmented by concrete perimeter piers poured to a depth of five to ten feet. When water intrudes under such a structure built on expansive soil, the piers heave.
Back to Top
Plumbing Failure, Plumbing Leak – When a foundation moves or fails, the plumbing system must move as well. As a foundation drops, the below slab plumbing is forced downward, and may break. Leaks in sewage lines as well as fresh water lines can lead to foundation failure.
Back to Top
Plumbing Test – As foundation failure may occur due to a plumbing leak, a leak test of the freshwater and gray water systems is required and performed after foundation repair.
Back to Top
Post for Pier and Beam – The foundation of a pier and beam house may be supported by wooden posts imbedded in the ground. In Texas Bodark tree wood was often used for the posts as it is resistant to rot. Wet soil will allow a Bodark post supported house to sink. Usually the sinking is uneven as the weight of the house exerts uneven pressures.
Back to Top
Post Tension Slab (Post tensioned Slab) – An enhancement over the conventional slab on grade foundation with much of the reinforcing steel (rebar), replaced by sleeved steel cables. The cables are put in place prior to pouring the slab and are tensioned about 3 days after the concrete is poured, when the concrete is still “green”. Such slabs are resistant to breaking, but may bend or twist. Time has shown that the post tensioned slab is not always adequate to withstand the forces of expansive clay soil.
Back to Top
Pressed Concreted Pilings – A method of foundation repair in which precast concrete cylinders are pressed as deeply as practical into the ground. The depth obtained is dependent upon the weight of the house, the soil type, and the soil moisture content.
Back to Top
Pushing Pilings or Piers to Refusal – During pressed piling installation, refusal is defined as an inability to press the piling any deeper. Depth to refusal is dependent upon piling driving pressure, surface friction of the piling, end bearing surface area of the piling, soil density, soil composition and soil moisture content. Pushing to refusal does not mean that the piling system is resting upon rock.
Back to Top
Refusal – In foundation repair, refusal means that the pressed piling system has been driven as deep as possible. The depth is limited by the weight of the house and the moisture content of the soil. When a pressed concrete piling driven to refusal, it is usually driven as deep as practical as limited by compressed soil. When a steel pier system is driven to refusal, it is normally driven to rock.
Back to Top
Registered Professional Engineer – A degreed engineer who has worked under a Registered Professional Engineer for 5 years, passed a set of exams and been certified by registered engineers as competent in an engineering discipline. The State of Texas does not license engineers for the specific discipline of foundation repair. Most cities require that a foundation repair plan be approved by a Registered Professional Engineer.
Back to Top
Roof Joist – Typically a 2×8 or 2×12, roof joists span the house and are often incorporated as a part of the ceiling. Spacing of roof joists is 16 or 24 inches.
Back to Top
Roof Movement – A failing foundation will cause the roof beams and joists to move. It is not uncommon to see a dip or hump in the roof ridge line when there is a foundation problem. Foundation failure may cause joists, beams and roofing to physically separate.
Back to Top
Roof Rafter – Typically a 2×6, rafters serve as the base for plywood upon which shingles or other roofing material is installed. Spacing of roof rafters is 16 or 24 inches.
Back to Top
Sagging Foundation – Describes when either the foundation center has dropped, or the ends have risen.
Back to Top
Seasonal Foundation Movement – As clay soil expands in the wet spring, and shrinks in the hot summer, we say that the foundation is subjected to seasonal foundation movement.
Back to Top
Seasonal Moisture Change – The load bearing capacity of soil may be affected by seasonal moisture change. In the Dallas Fort Worth area clay soil moisture content remains relatively consistent at approximately 12 feet below the surface. A pier system which does not extend below that depth may experience some seasonal movement.
Back to Top
Shim, Foundation Shimming – Many methods of foundation repair use spacers, called shims, to achieve optimal elevation. For concrete foundation repair, steel shims measuring ¼ inch by 4×4 inches are spaced between concrete cylinders or concrete blocks and the beam. Pier and Beam foundations are often supported by wooden shims which may compress. Steel shims are the best choice when shimming a pier and beam foundation.
Back to Top
Slab on Grade Foundation – Consists of interior and exterior beams and footings reinforced with steel. First introduced in the 50’s, slab on grade foundations have been significantly improved to sustain the forces of clay soils.
Back to Top
Soaker Hose – A porous garden hose which is used to increase the soil moisture content around a foundation perimeter. Soaker hoses are typically place 8 to 12 inches from a foundation. Water application with a soaker hose must be controlled to assure that the soil does not become super saturated and lose its load bearing capacity. Typically, the southwest corner of a foundation needs the most water and the north east corner requires the least water.
Back to Top
Soil Boring – By drilling a hole and removing a soil sample, an engineer is able to examine the characteristics of a soil. Field test and lab tests can be performed on bored samples. Boring cost is in the range of $1200-$5000, dependent upon the number of samples, sample depth, and analysis. Borings are essential to provide an understanding of underlying soil type, moisture, and compaction to enable the design of a proper foundation. Borings may be used in forensic evaluation when a foundation fails.
Back to Top
Soil Compaction – A mechanical method of increasing soil density, which increases the soil’s ability to support a foundation. Optimal compaction is obtained by compressing clay soils in layers of 4 inches or less. Foundation failure can arise when the soil is inadequately compacted.
Back to Top
Soil Consolidation – Settlement of soil under load. Uneven settlement of soil under the foundation can cause angular distortion and foundation failure.
Back to Top
Soil Creep – imperceptibly slow outward and downward movement of soil along a slope. Soil creep is a common cause of foundation failure on hillsides and may also occur due to inadequate retaining wall support.
Back to Top
Soil Cut / Fill – During the process of grading a residential foundation lot, high spots are removed or cut, exposing natural soil and low spots are filled. In residential construction, the cut soil tends to be well compacted, while the fill is poorly compacted, leading to foundation failure in the area of the fill.
Back to Top
Soil Plastic Limit – This is defined as the water content which will cause soil to crumble when rolled into a cylinder or thread like shape 3 ½ inches in diameter. In a more practical example, the plastic limit is when the soil changes from a solid to a plastic. The plastic limit occurs before the soil becomes mud. The plastic limit is used to characterize soils.
Back to Top
Soil Sample – A boring is performed and soil is extracted for analysis. Properties may include: type, expansiveness, consolidation, and presence of organic matter (such as roots). Soil sampling and evaluation is important to design a proper foundation.
Back to Top
Soil Settlement under Foundation – As soil compacts, collapses or compresses, the foundation moves downward. Soil settling under a foundation can continue for decades. Remedial repair of a settling foundation often includes installation of piers/pilings.
Back to Top
Soil Shear strength – The maximum shear stress that a soil or rock can sustain. When shear failure occurs, the soil is no longer able to provide adequate foundation support and the foundation may fail.
Back to Top
Soil Slope Failure – A slope failure occurs when there is slip along a surface. A most severe form of sloe failure is a land slide. Moderate amounts of slope failure can cause the soil to fail to support the foundation. Foundation underpinning is required to support the foundation as it is seldom economically feasible to place adequately compacted soil under an existing foundation.
Back to Top
Soil Stabilization – The treatment of soil to improve properties. Soil can be stabilized by addition of chemicals or by drainage. Clay soil stabilization consists of adding chemicals to decrease the expansive nature of clay in water. Soil stabilization is seldom performed for residential foundations.
Back to Top
Soil Swell – A volumetric increase in clay soil volume caused by an increase in water content. In the Dallas Fort Worth area of Texas, soil may swell 6 inches or more, which causes extreme stress to residential and commercial foundations.
Back to Top
Steel Pier / Piling – In the Dallas Fort Worth area steel piers typically provide the best long term foundation repair. Straight steel piers are driven to rock. Contrast this with poured piers or pressed concrete underpinning, which is typically supported by compressed soil.
Back to Top
Texas Residential Construction Commission (TRCC) – The mission of the Texas Residential Construction Commission is to promote quality construction for Texans by registering industry members and residential construction projects; providing information and educating homeowners and the residential construction industry; acting as a resource for complainants; and offering a neutral, technical review of alleged post-construction defects. The TRCC specifies that new home foundations and other structural elements be warranted by the builder for 10 years against construction defects. The TRCC does not oversee or regulate the foundation repair industry.
Back to Top
Urethane Injection – An expansive urethane foam is injected into drilled holes in a foundation floor. As the urethane foam expands, it lifts the foundation. The repair method is similar to that of mudjacking, but without adding moisture to the soil beneath the slab.
Back to Top
Vertical Expansive Soil Movement – Typically foundations are subjected to cyclical up and down movement as clay soil expands wet periods and contracts during dry periods. Under a foundation a clay soil may swell due to increased moisture content arising from plumbing leaks or the capillary action of water in dead tree roots.
Back to Top
Void – An airspace that exists between the bottom of the foundation floor and the soil. Current building practice is that soil shall be wet, maximally expanded when the concrete is poured. As the foundation ages and the soil achieves a lower, more stable level of moisture, a void or air pocket will form between the floor and the soil. A void is also created when a foundation is lifted.
Back to Top
Void Fill – Void fill is a process of injecting a slurry mixture of soil and possibly cement to fill the air void after a foundation is lifted. If clay soil is not at its maximally expanded state prior to the injection of the slurry, the clay may expand and damage the foundation. Normally the soil under a foundation has only a moderate moisture level and is not at its maximally expanded state. This is why void fill is rarely performed in the Dallas Fort Worth area.
Back to Top
Walking Brick – A brick wall is said to walk when it slips along the base of a foundation. This is caused by repeated sag and upheaval of a foundation. The gap thus formed by a separation of brick at the base of a wall will typically not close when the foundation is lifted. When brick have walked the brick wall must re-built to close the gap.
Back to Top
Schedule a FREE Inspection
Honest foundation repair in the Dallas, TX area. Leave your information and we’ll be in touch!