Structure

• Abutment

  The structure at the end of a bridge or arch that receives its vertical load and resists its outward thrust.

• Anchor bolt

  An anchor bolt is a robust structural fastener used to securely connect structural and non-structural elements to concrete or masonry foundations. Functioning as a critical link in the building envelope, these bolts are either cast into wet concrete during the initial pour or retrofitted into hardened surfaces to transfer tensile, shear, and compressive loads from the structure into the stable base. They are essential for ensuring the stability and safety of various constructions, ranging from securing steel columns and heavy machinery to mounting light poles and bridge railings, particularly in environments prone to high winds or seismic activity. Available in diverse designs such as L-shaped, headed, or expansion types, anchor bolts are typically made from carbon, stainless, or galvanized steel to provide long-term durability and resistance to movement or displacement.

• Arch

  A curved structural element that spans an opening and supports the weight above it. An arch transfers loads through compression along its curve, directing them into the supporting piers or abutments on either side.

• Beam

  A structural member that spans between supports and carries loads acting across its length. Beams are commonly horizontal and transfer floor, roof, or wall loads to columns or bearing walls.

• Blocking

  Blocking refers to the use of short pieces of dimensional lumber or metal members inserted between structural framing components, such as studs, joists, or rafters, to provide additional stability and support. Functioning as a vital reinforcement within wood or light-gauge steel frames, it serves to prevent the twisting or buckling of longer members under load while acting as a firestop to inhibit the spread of flames through concealed wall cavities. Beyond its structural role in maintaining the integrity of the building envelope, blocking provides a solid, secure nailing surface for the attachment of finish materials and heavy fixtures, including cabinets, shelving, handrails, and wall-mounted hardware.

• Brace

  A brace is a structural element designed to provide stability and support by preventing unwanted movement or deformation in buildings and other construction projects. Typically installed diagonally, horizontally, or vertically between structural components, its primary function is to resist lateral forces such as wind loads and seismic activity by transferring these stresses efficiently through the framework to the ground. Bracing is essential for maintaining the structural integrity and vertical alignment of a building, preventing issues like buckling, swaying, or collapse. While often constructed from high-strength materials like steel or timber to handle tension and compression, braces can also serve an aesthetic purpose when left exposed as a design feature to create visual interest and emphasize a structure’s engineering. Common configurations include cross-bracing, K-bracing, and V-bracing, each selected based on the specific load requirements and architectural needs of the project.

• Buttress

  A mass of masonry built against or projecting from a wall to resist the lateral thrust of arches, vaults, or roofs.

• Cantilever

  A structural member fixed at one end and free at the other, projecting beyond its support to carry balconies, canopies, or overhangs.

• Dome

  A rounded vault forming the roof of a building, typically raised over a circular, elliptical, or polygonal base.

• Foundation

  A foundation is the critical structural base of a building that anchors the superstructure to the ground and transmits its total load to the underlying soil or rock. By distributing the weight of the structure over a broad area, it prevents uneven settlement and ensures long-term stability against external forces such as wind, seismic activity, and soil movement. Foundations also function as a protective barrier, shielding the building from ground moisture, frost heaves, and temperature fluctuations. Depending on soil conditions and building height, they can range from shallow systems like spread footings and slabs to deep systems like piles and caissons that reach stable strata far below the surface.

• Girder

  A girder is a primary horizontal structural element designed to support heavy vertical loads and span long distances between main supports such as columns, piers, or walls. Functioning as the backbone of a building's or bridge's framing system, it carries the weight of smaller secondary beams, joists, and floor or roof decks, efficiently transferring these accumulated loads to the foundation. Girders are typically larger and more rigid than standard beams to resist bending and shear forces, and they are commonly fabricated from high-strength materials like structural steel, reinforced concrete, or engineered wood. Their ability to manage significant spans makes them essential for creating large open spaces in commercial, industrial, and infrastructure projects.

• Header

  A header is a critical horizontal structural member that spans an opening in a wall, such as a window, door, or interior passageway. Its primary function is to act as a bridge, collecting the vertical loads from the structure above—including the roof, floors, and wall studs—and redistributing that weight to the vertical support members, known as jack studs, on either side of the opening. Typically constructed from dimensional lumber, steel, or engineered wood products like Laminated Veneer Lumber (LVL), headers ensure the structural integrity of the building envelope by preventing sagging, cracking, or failure of the wall where the continuous load path has been interrupted. While often concealed within the wall framing, headers are essential components in both load-bearing and non-load-bearing applications, with their depth and thickness determined by the span of the opening and the magnitude of the anticipated loads.

• Joist

  One of a series of parallel horizontal members spanning between walls or beams to support a floor or ceiling.

• Keystone

  The wedge-shaped stone at the crown of a masonry arch. It completes the arch ring and is sometimes enlarged or decorated to emphasize the center of the opening.

• Laminated Veneer Lumber

  Laminated veneer lumber (LVL) is a high-strength engineered wood product manufactured by bonding multiple layers of thin wood veneers together with structural adhesives under heat and pressure. Unlike plywood, where grains are layered perpendicularly, LVL veneers are typically oriented in the same direction, resulting in a product that is stronger, straighter, and more uniform than solid-sawn timber. This manufacturing process disperses natural defects like knots throughout the material, providing high load-bearing capacity and dimensional stability that makes it less prone to warping, shrinking, or splitting. Widely used in both residential and commercial construction, LVL serves as a versatile structural component for headers, beams, rafters, and joists, often allowing for longer spans and heavier loads than conventional lumber.

• Lintel

  A horizontal member that spans an opening in a wall, such as a doorway or window, and supports the construction above. Unlike an arch, a lintel primarily carries load through bending.

• Load-bearing wall

  A load-bearing wall is an active structural element of a building that supports the weight of the elements above it, such as floors, roofs, and beams, and transfers that weight to the foundation. Constructed from durable materials like concrete, brick, stone, or steel, these walls are essential for maintaining a structure's stability and integrity. Unlike non-load-bearing partition walls, which only serve to divide interior spaces, load-bearing walls cannot be removed or significantly altered without providing alternative structural support to prevent potential collapse. They are typically found on the perimeter of a building and often run perpendicular to floor or roof joists.

• Mass timber

  Structural framing made from large prefabricated engineered wood elements, such as cross-laminated timber (CLT) panels and glulam beams and columns.

• Non-load-bearing wall

  A non-load-bearing wall, also known as a partition wall, is a structural element designed to divide interior spaces and provide privacy without supporting any vertical loads other than its own weight. Unlike load-bearing walls, which transfer the weight of the roof and upper floors to the foundation, non-load-bearing walls can typically be removed or relocated during renovations without compromising the building's structural integrity. These walls are often constructed from lightweight materials such as drywall, glass, or timber and are frequently used in modern steel-frame or concrete-frame buildings as an adaptable "skin" or interior divider to define rooms, hallways, and functional zones. In addition to organizing space, they can serve as barriers for fire protection and sound attenuation, and they often house essential utilities like electrical wiring and plumbing.

• Oculus

  A circular opening at the crown of a dome or set into a wall, admitting light and air. The Pantheon in Rome has the best-known example.

• Post

  A post is a primary vertical structural element, typically made of timber, metal, or stone, used to support loads from beams, girders, roofs, or floors and transfer them to the foundation or ground. While functionally similar to a column or pier, posts are often distinguished by their smaller scale and square or rectangular profiles, and they serve as the fundamental upright components in post-and-beam, post-and-lintel, and timber-frame construction. Beyond their essential role in maintaining a building's structural integrity and stability, posts are versatile elements used in various applications, including porch and deck supports, fencing, and pergolas, where they can be left exposed to contribute to the architectural character and aesthetic of a space.

• Shear wall

  A shear wall is a specialized vertical structural element designed to resist in-plane lateral forces, such as those generated by high winds or seismic activity. Unlike standard load-bearing walls that primarily support vertical weights, shear walls act as rigid diaphragms that transfer horizontal loads to the building's foundation, preventing the structure from swaying, racking, or collapsing sideways. Typically constructed from reinforced concrete, steel plates, or structural wood panels like plywood or OSB, these walls are strategically placed—often around elevator cores or at the building's perimeter—to ensure structural symmetry and stability. By absorbing and distributing the energy from external environmental pressures, shear walls maintain the integrity of the building envelope and are a critical safety component in high-rise construction and regions prone to severe weather.

• Slab

  A slab is a flat, horizontal structural element, typically made of reinforced concrete, that forms the floors, roofs, and ceilings of modern buildings. Functioning as a primary load-bearing component, it provides a level surface while distributing the weight of occupants, furniture, and the structure itself to supporting beams, columns, or the foundation. Slabs can be classified based on their support system, such as ground-bearing slabs that rest directly on the subsoil or suspended slabs that span between supports. They are available in various configurations, including one-way and two-way systems, as well as specialized designs like waffle and ribbed slabs, which optimize strength and material efficiency for different architectural spans and loads. Beyond their structural role, slabs contribute to a building's performance by providing thermal mass and acting as barriers against fire and sound.

• Slab-on-grade

  Slab-on-grade is a structural engineering practice where a concrete slab is poured directly onto a prepared ground surface to serve as both the building's foundation and its primary subfloor. This monolithic system is typically reinforced with rebar or wire mesh and is often thickened at the edges or under load-bearing walls to ensure structural integrity and load distribution. Because it eliminates the need for a basement or crawl space, this method is often more cost-effective, faster to construct, and resistant to pests and moisture issues. While traditionally preferred in warmer climates to avoid frost heave, modern advances in insulation, such as frost-protected shallow foundations, allow slab-on-grade construction to be an energy-efficient and accessible solution for a wide range of residential and commercial structures.

• Spandrel

  The roughly triangular area between the curve of an arch and its rectangular frame, or between adjacent arches; in curtain walls, the opaque panel between floors.

• Stem wall

  A stem wall is a short, vertical foundation wall that transmits structural loads from a building to its footing, providing a stable transition between the ground and the main structure. Typically constructed from poured concrete or masonry blocks reinforced with steel rebar, it serves as a critical perimeter support that elevates the building's floor system above grade. This elevation protects the structure from moisture infiltration, flooding, and pests while often creating a functional crawlspace for accessing plumbing and electrical systems. By distributing the weight of the structure evenly over the footing, stem walls mitigate the risks of uneven settling and are especially effective on sloped sites where the wall height can be varied to maintain a level building platform.

• Stud

  One of a series of vertical members in a framed wall, carrying loads to the floor or foundation and providing fixing for wall linings.

• Vault

  An arched form used to cover a space with a ceiling or roof. A barrel vault is a continuous arch extended along an axis; intersecting vaults form groin and rib vaults.

• X-bracing

  A pair of diagonal members crossing within a frame bay to resist sideways forces from wind or earthquakes by turning them into tension and compression.

• Y-column

  A column that splits into two inclined arms near the top, gathering loads from two points of a roof or floor into a single support.