ANCHOR BOLT: A steel bolt anchoring a wood frame structure to the foundation. Current UBC Code requires anchor bolts at 6" centers and within 4" to 12" of the end of each sill board.

BEARING PILE: A shaft or column drilled or driven into the ground to act as a foundation by transferring the load that it supports to the very firm soil or bedrock on which it rests.

BEDROCK: The solid crust of the earth, which may be exposed at the surface or located several hundred feet below the surface.

CAP: A concrete pad that ties the top end of a pile group together either in a cluster or row, which in turn supports a column or wall.

CATCH BASIN: Surface drain inlet with grate (also "drop inlet").

COSMETIC: Minor distress that does not impact structural integrity, i.e. drywall cracks, door offsets.

CREEP: The slow down slope movement of near surface soils usually related to annual wetting and drying cycles of expansive clay soils or poorly consolidated fill.

CRIPPLE WALL: The wall in the crawl space of a home between the foundation and home’s first floor.

CUT: The ground surface remaining after the removal of soil by excavation.

EARTH TO WOOD SEPARATION: Current UBC Code and good construction practice requires a 6" separation between soil and the wood elements of a home to minimize pest infestation and rot problems.

EFFLORESCENCE: An indication of excessive moisture resulting in a white salt deposit remaining on a concrete surface after repeated drying cycles (also calcium deposit).

END BEARING PIER: A drilled or driven shaft, extended to bedrock, providing foundation support.

EXCAVATION: The digging out and removal of soil from a site.

EXPANSIVE SOIL: A type of clay soil which expands when moisture is added and shrinks during drying cycles.

FILL: The material used to fill & level, or adjust the grade of, a sloping site or to rebuild the base of an excavation to the required height (imported, not native soil).

FINGER DRAIN: A finger drain is constructed much like a sub-drain, but is typically positioned in the sub-area, just inside the perimeter foundation. A finger drain is typically 8” wide and varies in depth from 6” to 15” and often outlets to an 18” diameter, 30” deep, cased sump that is provided with a float-switch activated pump.

FLOATING FOUNDATION: A continuous spread footing foundation that extends under an entire building replacing many separate footings (also "mat").

FLOOR JOISTS: any of the small timbers or metal beams ranged parallel from wall to wall in a structure to support a floor or ceiling.
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FOOTING: The portion of the foundation that bears on the supporting soil.

FORM WORK: The temporary mold into which liquid concrete is poured to create a specific shape and the associated structure.

FOUNDATIONS: The structural system constructed below a building that transfers the vertical weight and lateral loads of the building to the ground on which it stands.

FOUNDATION WALL: A wall (usually poured concrete or concrete block) built below ground level to transfer the weight of the exposed wall it supports to the footing on which it rests (also stem wall).

FRICTION PIER: A drilled or driven shaft extended into the ground normally filled with reinforced concrete which provide support through friction between the piers surface and the soil.

FRICTION PILE: A shaft or column that is drilled or hammered into the ground until the pressure or friction developed between the pile surface and the soil into which it is forced (driven) enables it to become a firm foundation support on which, when combined or grouped with other piles, to build heavy structures.

GRADE: Soil surface or the inclination of a pipe or the property (also site slope). Grade is often expressed as a ratio of the horizontal to the vertical components of slope i.e. 2:1.

GRADE BEAM: A reinforced concrete foundation element used to distribute building loads to foundations piers and to interconnect the piers.

HONEYCOMB: Voids in concrete typically resulting from inadequate vibration during placement (also "popcorn concrete").

INVERT: The lowest point on the inside surface of a pipe or channel.

LANDSLIDE: A slope failure resulting in the downward movement of a section of a hillside.

LATERAL LOAD: A horizontally applied force typically resulting from seismic loads on foundations and wind loads on walls.

PIER: A column or shaft (also caisson) in the ground that serves as a foundation constructed by drilling a hole and filling it with concrete and reinforcing steel.

PIPE PILES: A type of underpinning in which steel pipes are driven into the ground below an existing foundation to provide stable support (also mini-pile).

PONY WALL: A less than standard height stud wall (also known as a cripple wall). It is usually employed to provide support between the foundation and the floor on a sloping site.

REINFORCING: The deformed steel rods or mesh embedded in concrete to strengthen it.

RETAINING WALL: A wall built to retain soil or support a foundation on sloping ground. The Uniform Building Code requires walls over 4 feet to be designed by a licensed Civil or Structural Engineer.

SEISMIC STRAP: A steel strap used to restrain the structure or an element of the structure from the lateral forces developed during earthquakes by connecting the frame to the foundation (also "tie-down). The term used to describe the exact location of a building.

SHEARPLY: Plywood reinforcement used to improve the strength of stud walls to resist lateral loads (earthquake forces).

SHEAR TRANSFER TIE: A metal brace nailed into both the shear wall and the floor joists that allows the shear wall to support the house during the shaking of an earthquake.

SHEAR WALL: Sheets of plywood nailed to the studs of an exterior wall, such as a cripple wall, to provide bracing against the shaking forces of an earthquake.

SILL: The first wood element above the foundation (also mudsill).

SIMPSON: A manufacturer of steel connectors for wood frame construction.

SLAB: A flat, thin, horizontal concrete element.
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SLIPOUT: A small slope failure that moves (also "mud flow").

SLOPE: The degree to which a surface tends upward or downward – see definition for GRADE

SOFT STORY: An open area, commonly a garage, at ground level with a room directly above it. Because of the garage door, one wall of the house can’t be secured with shear wall.

SOIL PROFILE: A vertical cross-section drawing of the ground showing the type and depth of each layer of material between the surface and bedrock.

SPOT FOOTER: A spot or pad footing is used to support a single point of contact, such as under a pier or post.

SPREAD FOOTING FOUNDATION: A very common type of foundation that involves placing a wide flat concrete footing under the perimeter building walls distributing the weight over a greater area.

STANDING WATER: Water within the crawl space that has not evaporated or percolated away.

STEM WALL: The portion of the foundation above the footing that supports the wood frame by connection to the sill plate.

SUBDRAIN: A subsurface moisture collection system normally designed to cut off underground water flow (also "back drain", "curtain drain" or "french drain").

SWALE: Linear depression which forms a drainage channel.

UBC: Uniform Building Code; the code that each building permit authority uses as a basis for review and acceptance at residential design and construction (the code is updated periodically).

UNDERPINNING: Added foundation support placed under an existing building foundation.

WATERPROOF MEMBRANE: An impermeable barrier placed to prevent moisture intrusion.

WATER TABLE: The distance below the surface at which the soil is completely saturated with water. A perched water table can develop above the actual water table when a clay lens or other impermeable layer prevents or delays vertical percolation.