We have compiled some useful definitions to help you navigate through the lingo of engineering, foundation repair and construction. The definitions are not in alphabetical orders but instead in sequential order in a discussion format. Visit this site often as we will update the list from time to time:
Beam: A structural member that is positioned in horizontal direction and spans between columns or supports. The most common place for a beam is over a door, window or large opening in a wall. Beams are also called girders. The beams typically carry floor joists, roof rafters or ceiling joists. Beams can be of various sizes and material: steel, wood, concrete, etc. Choosing the right beam for the project will depend on the load it has to carry, the span it has to cross and the supports at the ends. A beam can be constructed of wood, concrete or steel. One special characteristic of beams is that they are designed to bend to some degree.
Column: A column is a vertical (standing up) member that supports beams. The column carries loads into the foundation. Columns can be constructed with wood, steel, concrete or masonry.
Foundation: A foundation is a structural element that is in direct concrete with the soil. The foundation can be constructed with any material. The main point here is that the foundation is the structural member that is contact with the soil and carries the load from the building to the soils. Consider the foundation as the medium between the soil and the building. The foundation can be constructed with wood, masonry, concrete or rubble. The easiest way to identify the foundation is to identify the structural member that sits on or in the soil.
Footing: A footing a foundation element that typically has a square or circular shape. Footings are designed to carry column loads to the soil. The footing size is dependent on the amount of load it has to carry and the allowable capacity of the soil to support the load. The heavier the load, the bigger the footing. The weaker the soil the bigger the footing.
Bending: Bending is similar to deflection. The main difference between deflection and bending is that deflection happens when a load is applied to a structural member whereas bending is
Deflection: Deflection is the bending of structural member due to an applied load. For example, a beam is supported by a column at each end. A load from the roof might sit on the beam and therefore the beam can deflect downward (as known as bending) because of the load. All structural beams are designed and will deflect to some degree when a load is applied. Just because a member bends or deflects does not mean that it has structurally failed.
Stiffness: Stiffness is the ability of a structural member to resist bending or deflection. The stiffer the member or system, the less deflection and bending that it will experience. Every structural beam and foundation has some degree for stiffness. Again, the stiffer the foundation or the beam, the less that it will deflect or bend. Keep in mind that deflection or bending does not meet structural failure.
Tilt: Tilt is the planar rotation of a foundation. In simpler terms, assume you pick up a plate and tilt it over without bending it. The tilting of the plate is similar in manner as to how foundations tilt. Why do foundations tilt you may ask? Most foundations that tilt sit on clay or sandy soils AND are built on sloping properties or hills. Whether the clay is expansive or non-expansive doesn’t really make a difference but simply that the foundation sits on soil and not rock. Foundation tilt happens when the soils supporting the house/building self-consolidate or “settle” because of the applied pressure of the house. The soils will consolidate or settle in the direction of the hill that the house is built on. So, if your house or building is constructed on the side of small and hill (even small rolling hills) your foundation is likely to have some degree of foundation tilt down the hill. Foundation tilt is not foundation failure nor does it suggest foundation failure. Two final points, the amount of foundation tilt is not likely to exceed the amount of slope of the hill. The second point is that foundations with tilt commonly get misdiagnosed as foundations with problems because of the sloping floors. Reversing the effects of foundation tilt with foundation repair can break the building. Consult with a structural engineer to help you determine if your foundation is tilting, deflecting or both.
Expansive Soils: Without getting too technical, expansive soils are soils that will swell excessively when they absorb water. However, those same expansive soils will shrink excessively as they dry up. For this reason, you might find some references that tell you to water the foundation or add soaker houses. The idea behind adding soaker hoses or water the foundation is to try to keep expansive soils moist so that during a drought they don’t shrink as much; which can cause the foundation to settle. Foundation repair companies will tell you that their foundation pile will “stabilize” the foundation BUT be cautious on this claim. Consult with a structural engineer on how piles impact the foundation.
Non-Expansive Soils: Non expansive soils are typically sands and silts. Nonexpansive soils do not swell up excessively (as do expansive soils) when they get wet. However, nonexpansive soils are more likely to settle with or without water. They tend to settle with pressure. Nonexpansive soils can also settle when they dry but the settlement due to drying is minimal in comparison with expansive soils.
Foundation Stabilization (Foundation Repair Industry): Foundation repair companies will attempt to “stabilize” your foundation in one direction only; which is in the downward direction. Its important to understand the term “stabilization” or ask the foundation repair company to explain to you what they mean by it. Recall the definition for expansive soils. Expansive soils will swell when wet and settle when they dry. Let’s assume that your foundation gets evaluated by the foundation repair company and you are told that the perimeter is 1”, 2” or 4” lower than the interior. You may be told that the perimeter has “settled” and that the foundation repair company will raise the perimeter and “stabilize” it. Consult with a structural engineer on this before you buy it.
Foundation Stabilization (Structural Engineering Industry): To a structural engineer, stabilization means little to no movement. Little to no movement is not likely to happen. Foundation are designed to move so “stabilizing” a foundation against future movement is not likely to happen if we follow accepted engineering principles. Structural engineers use materials, geometry and physics to “engineer” the stiffness, shape and location of structural members (foundations, beams, columns, etc.) to reduce the amount of movement to some a degree that doesn’t cause a lot of damage to the building. Consult with a structural engineer on how your building maybe designed to perform. This might be able to help you understand the tolerance for your building and whether or not you need to “fix” something.
Relative Elevations (foundation elevations): Foundation elevations are readings taken across the top of the foundation or floor using manometers, water levels or some type of elevation measuring device. The idea is to note the relative differences between two arbitrary points throughout the house/building relative to a reference or set zero point. For example, say you have a perfectly square floor plan or house and we set the reference point for the readings at the exact middle of the house. Using a meter, we note the elevation readings of the corners, walls, rooms and everywhere else throughout the house. Those readings will be shown as -1/2”, ¾”, 0.78’, 0.55”, 0” etc., or some measurement format. Those readings tell you the difference between the spot where the measurement was taken and the reference point. Be cautious in reading the elevations. Differences in elevations does not mean the foundation has moved or is failing. Consult with a structural engineer to help explain the readings and interpretation of the readings relative to the condition of your house.
Foundation Leveling: Foundation leveling is the operation of lifting areas or the entire foundation to a relative level position. Level does not always mean zero differences in elevation. The first step in “leveling a foundation” is to record the elevation readings before the lift and then record the elevation readings after the lift. Leveling a foundation should not be considered “foundation repair” or “foundation fix”. Leveling is not a “repair”, “fix” or “stabilization”. It’s just leveling. Consult with a structural engineer to help explain the differences between leveling, stabilization, fix, repairs and foundation repair to help understand the risks before you get foundation repair.
*** We are currently adding the following definitions so please check back with us soon ***
Cast in Place Pier:
Deep Driven Pile:
Concrete Segmental Pile:
Post Tension Slab on Grade:
Conventionally Reinforced Slab on Grade:
Stiffened Slab on Grade:
Roof Truss System:
Roof 2x Conventional Framing
Imposed Service Loads:
Wire Mesh / Wire Fabric:
International Residential Code (IRC):
International Building Code (IBC):
Uniform Building Code (UBC):
Load Bearing Wall:
Segmental Retaining Wall (SRW):
Cantilever Concrete Retaining Wall: