A tie, strap, tie rod, eyebar, guy-wire, suspension cables, or wire ropes, are examples of linear structural components designed to resist tension. [1] It is the opposite of a strut or column, which is designed to resist compression. Ties may be made of any tension resisting material.
In wood-frame construction ties are generally made of galvanized steel. [2] Wood framing ties generally have holes allowing them to be fastened to the wood structure by nails or screws. The number and type of nails are specific to the tie and its use. The manufacturer generally specifies information as to the connection method for each of their products. Among the most common wood framing ties used is the hurricane tie or seismic tie used in the framing of wooden structures where wind uplift or seismic overturning is a concern.
A hurricane tie (also known as hurricane clip or strip) is used to help make a structure (specifically wooden structures) more resistant to high winds (such as in hurricanes), resisting uplift, racking, overturning, and sliding. [3] Each of the crucial connections in a structure, that would otherwise fail under the pressures of high winds, have a corresponding type of tie, generally made of galvanized or stainless steel, and intended to resist hurricane-force and other strong winds. [4]
"Hurricane clip" has two meanings in building construction:
Seismic ties are used to securely fix cabinets, bookcases, desks, appliances, machinery & equipment to walls and/or floors to constrain their movement during earthquakes. [6]
Top mount, face mount, sloped/skewed, and variable pitch hangers for dimensional lumber, engineered wood I-joists, structural composite lumber and masonry wall. To give added strength in increase various load requirements over wood only.
Joist hangers are used to prevent floor joists, which is what supports the flooring systems in residential homes and buildings built using lumber, from dropping and twisting thus creating an uneven walking surface. This is known as floor sagging. It is important to note that when laying wooden subfloor to apply adhesive to the joists which the subfloor will lay on to help prevent creaking & lateral movement and separation of the joists and subfloor. Using screws instead of nails is also highly recommended to prevent the aforementioned creaking and other problems as well. Subfloor isn't load bearing in residential construction. Although the use of steel joist hangers to support floor joists is recommended over a ledger supporting the joists because of house settling and nail separation, they are not required by code in most municipalities. However, toe nailing & end nailing is nowhere near as effective as using hangers to support flooring systems. [7]
Twist straps provide a tension connection between two wood members. They resist uplift at the heel of a truss economically. When the strengthening is being done from the inside, the ideal connector to use is one that connects rafters or trusses directly to wall studs. This can only be done where the rafter or trusses are immediately above or immediately to the side of studs below. In that case a twist strap connector can be used. [8]
A connector for connecting wall studs of two adjacent floors in a light frame building structure, the connector having a first attachment tab, a seat member, a diagonally slanted support leg, and a second attachment tab, all substantially planar. The connector is intended to be paired and the paired connectors joined by an elongated tie member that pierces the sill plates of the intervening floor structure.
Sometimes referred to as an angle brace. The Angle tie is used to prevent displacement of building elements due to thrust. A brace/tie across an interior angle of a wooden frame, forming the hypotenuse and securing the two side pieces together. [9]
Similar to a French cleat, a Z-Clip allows for the installation of wall panels without screwing into the front of the panels. The clips provide a secure mount for wall panels, partitions, frames, cabinets, and more. Once installed, clips wedge together to lock panels in place. To disengage panels, simply lift and remove.
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Rafter ties are designed to tie together the bottoms of opposing rafters on a roof, to resist the outward thrust where the roof meets the house ceiling and walls. This helps keep walls from spreading due to the weight of the roof and anything on it, notably wet snow. In many or most homes, the ceiling joists also serve as the rafter ties. When the walls spread, the roof ridge will sag. A sagging ridge is one clue that the home may lack adequate rafter ties. Rafter ties form the bottom chord of a simple triangular roof truss. They resist the out-thrust of a triangle that's trying to flatten under the roof's own weight or snow load. They are placed in the bottom one-third of the roof height. Rafter ties are always required unless the roof has a structural (self-supporting) ridge, or is built using engineered trusses. A lack of rafter ties is a serious structural issue in a conventionally-framed roof.
A wooden beam serving this purpose is known as a tie-beam, and a roof incorporating tie-beams is known as a tie-beam roof. [10]
A wall is a structure and a surface that defines an area; carries a load; provides security, shelter, or soundproofing; or, is decorative. There are many kinds of walls, including:
Lumber is wood that has been processed into uniform and useful sizes, including beams and planks or boards. Lumber is mainly used for construction framing, as well as finishing. Lumber has many uses beyond home building. Lumber is referred to as timber in the United Kingdom, Europe, Australia, and New Zealand, while in other parts of the world the term timber refers specifically to unprocessed wood fiber, such as cut logs or standing trees that have yet to be cut.
A floor is the bottom surface of a room or vehicle. Floors vary from simple dirt in a cave to many layered surfaces made with modern technology. Floors may be stone, wood, bamboo, metal or any other material that can support the expected load.
A truss is an assembly of members such as beams, connected by nodes, that creates a rigid structure.
Timber framing and "post-and-beam" construction are traditional methods of building with heavy timbers, creating structures using squared-off and carefully fitted and joined timbers with joints secured by large wooden pegs. If the structural frame of load-bearing timber is left exposed on the exterior of the building it may be referred to as half-timbered, and in many cases the infill between timbers will be used for decorative effect. The country most known for this kind of architecture is Germany, where timber-framed houses are spread all over the country.
Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries and late 1970s for many other parts of the world, many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the imminent problem, various research work has been carried out. State-of-the-art technical guidelines for seismic assessment, retrofit and rehabilitation have been published around the world – such as the ASCE-SEI 41 and the New Zealand Society for Earthquake Engineering (NZSEE)'s guidelines. These codes must be regularly updated; the 1994 Northridge earthquake brought to light the brittleness of welded steel frames, for example.
A soffit is an exterior or interior architectural feature, generally the horizontal, aloft underside of any construction element. Its archetypal form, sometimes incorporating or implying the projection of beams, rafters or trusses over the exterior of supporting walls, is the underside of eaves. The vertical band at the edge of the roof is called a fascia. A soffit of an arch is frequently called an intrados.
A joist is a horizontal structural member used in framing to span an open space, often between beams that subsequently transfer loads to vertical members. When incorporated into a floor framing system, joists serve to provide stiffness to the subfloor sheathing, allowing it to function as a horizontal diaphragm. Joists are often doubled or tripled, placed side by side, where conditions warrant, such as where wall partitions require support.
A framer is someone who builds or creates frames. In construction work, frames may be built from wood or metal and provide support and shape to a structure. In a related sense, framers may create frames for art works, pictures, or mirrors. The term framer is also used for the authors of a formal text such as a constitution.
Framing, in construction, is the fitting together of pieces to give a structure support and shape. Framing materials are usually wood, engineered wood, or structural steel. The alternative to framed construction is generally called mass wall construction, where horizontal layers of stacked materials such as log building, masonry, rammed earth, adobe, etc. are used without framing.
A plate or wall plate is a horizontal, structural, load-bearing member in wooden building framing.
A purlin is a longitudinal, horizontal, structural member in a roof. In traditional timber framing there are three basic types of purlin: purlin plate, principal purlin, and common purlin.
Domestic roof construction is the framing and roof covering which is found on most detached houses in cold and temperate climates. Such roofs are built with mostly timber, take a number of different shapes, and are covered with a variety of materials.
A king post is a central vertical post used in architectural or bridge designs, working in tension to support a beam below from a truss apex above.
Cold-formed steel (CFS) is the common term for steel products shaped by cold-working processes carried out near room temperature, such as rolling, pressing, stamping, bending, etc. Stock bars and sheets of cold-rolled steel (CRS) are commonly used in all areas of manufacturing. The terms are opposed to hot-formed steel and hot-rolled steel.
An engineered wood joist, more commonly known as an I-joist, is a product designed to eliminate problems that occur with conventional wood joists. Invented in 1969, the I-joist is an engineered wood product that has great strength in relation to its size and weight. The biggest notable difference from dimensional lumber is that the I-joist carries heavy loads with less lumber than a dimensional solid wood joist. As of 2005, approximately 50% of all wood light framed floors used I-joists. I-joists were designed to help eliminate typical problems that come with using solid lumber as joists.
A timber roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof. Trusses usually occur at regular intervals, linked by longitudinal timbers such as purlins. The space between each truss is known as a bay.
Toenailing or skew-nailing is a viable, structurally sound method of the driving of a nail at a roughly 30° angle to fasten two pieces of wood together, typically with their grains perpendicular. The term comes colloquially from fastening wood at the bottom, or toe, of the board. A variation of toenailing is to use screws, casually known as "toe-screwing". Toenails are typically driven in opposing pairs when possible, or pairs of pairs when appropriate. The angled nailing makes later dismantling difficult or destructive.
Tornadoes, cyclones, and other storms with strong winds damage or destroy many buildings. However, with proper design and construction, the damage to buildings by these forces can be greatly reduced. A variety of methods can help a building survive strong winds and storm surge.
American historic carpentry is the historic methods with which wooden buildings were built in what is now the United States since European settlement. A number of methods were used to form the wooden walls and the types of structural carpentry are often defined by the wall, floor, and roof construction such as log, timber framed, balloon framed, or stacked plank. Some types of historic houses are called plank houses but plank house has several meanings which are discussed below. Roofs were almost always framed with wood, sometimes with timber roof trusses. Stone and brick buildings also have some wood framing for floors, interior walls and roofs.
A long slender piece sustaining tension is called a tie. One sustaining compression is called a strut or post.