A tie,
strap,
tie rod
A tie rod or tie bar (also known as a hanger rod if vertical) is a slender structural unit used as a tie and (in most applications) capable of carrying tensile loads only.
It is any rod or bar-shaped structural member designed to prevent the separa ...
,
eyebar
In structural engineering and construction, an eyebar is a straight bar, usually of metal, with a hole ("eye") at each end for fixing to other components. Eyebars are used in structures such as bridges, in settings in which only tension, and ne ...
,
guy-wire
A guy-wire, guy-line, guy-rope, or stay, also called simply a guy, is a tensioned cable designed to add stability to a free-standing structure. They are used commonly for ship masts, radio masts, wind turbines, utility poles, and tents. A ...
, suspension cables, or wire ropes, are examples of linear
structural components designed to resist
tension
Tension may refer to:
Science
* Psychological stress
* Tension (physics), a force related to the stretching of an object (the opposite of compression)
* Tension (geology), a stress which stretches rocks in two opposite directions
* Voltage or el ...
. It is the opposite of a
strut
A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension.
Human anatomy
Part of the functionality o ...
or
column, which is designed to resist compression. Ties may be made of any tension resisting material.
Application in wood construction
In wood-frame construction ties are generally made of
galvanized
Galvanization or galvanizing ( also spelled galvanisation or galvanising) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged ...
steel.
Wood framing ties generally have holes allowing them to be fastened to the wood structure by
nails or
screw
A screw and a bolt (see '' Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helical ridge, called a ''male thread'' (external thread). Screws and bolts are used to f ...
s. 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
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...
tie or
seismic
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other ...
tie used in the
framing of wooden structures where wind uplift or seismic overturning is a concern.
Hurricane tie
A hurricane tie is used to help make a structure (specifically
wooden structures) more resistant to high winds (such as in
hurricane
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...
s), resisting uplift, racking, overturning, and sliding.
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
Galvanization or galvanizing ( also spelled galvanisation or galvanising) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged ...
or
stainless steel, and intended to resist hurricane-force and other strong winds.
[Rumbarger, Janet, Richard Vitullo, and Charles George Ramsey. ''Architectural graphic standards for residential construction''. New York: John Wiley & Sons, 2003. 238. Print.]
A connecting tie that provides a continuous structural load transfer path from the top of a building to its foundation, helping to protect buildings from damage resulting from high wind. These devices are primarily used in areas affected by high winds including hurricanes and are generally suitable for any area that may be impacted by windstorm damage. They are also known as hurricane clip or strips. Among the most common style used along the
Gulf Coast of the United States are
plywood fasteners or
oriented strand board
Oriented strand board (OSB) is a type of engineered wood similar to particle board, formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations. It was invented by Armin Elmendorf in California in 1963 ...
s over the windows and openings of brick homes. Hurricane clips meet the minimum requirements for code approval and are only as strong as their weakest install point; which is generally half the strength of the wood.
A hurricane clip has two meanings in building construction:
* A connecting tie that provides a continuous structural load transfer path from the top of a building to its foundation, helping to protect buildings from damage resulting from high wind. These devices are primarily used in areas affected by high winds including
hurricane
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...
s and are generally suitable for any area that may be impacted by windstorm damage. They are also known as hurricane ''ties''
or ''strips'';
* A tie which is attached to roof tiles to keep them from blowing off a roof. These devices are also known as ''wind clips'' and ''hurricane side clips''
Seismic tie
Seismic tie provides facility to securely fix cabinets, bookcases, desks, appliances, machinery & equipment to walls and/or floors to constrain their movement during earthquakes.
Girder tiedown
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 hanger or corner bracket
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.
Twist strap
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.
Floor span connector
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.
Angle tie
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.
Z-clip
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.
Plate
See
Rafter tie (and tie-beams)
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
joist
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 su ...
s 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.
See also
*
Framing (construction)
*
Timber framing
Timber framing (german: Holzfachwerk) 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 ...
*
List of structural elements Structural elements are used in structural analysis to split a complex structure into simple elements. Within a structure, an element cannot be broken down (decomposed) into parts of different kinds (e.g., beam or column).
Structural elements can ...
*
Tie rod
A tie rod or tie bar (also known as a hanger rod if vertical) is a slender structural unit used as a tie and (in most applications) capable of carrying tensile loads only.
It is any rod or bar-shaped structural member designed to prevent the separa ...
References
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Fasteners