
[Middle English giste, joiste, from Old French giste, from feminine past participle of gesir, to lie, lie down, from Latin iacēre.]
One of a series of parallel beams of timber, reinforced concrete, or steel used to support floor and ceiling loads, and supported in turn by larger beams, girders, or bearing walls; the widest dimension is vertically oriented. Also see binding joist, boarding joist, bridging joist, ceiling joist, common joist, floor joist, principal joist, sleeper joist.
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A joist, in architecture and engineering, is one of the horizontal supporting members that run from wall to wall, wall to beam, or beam to beam to support a ceiling, roof, or floor. It may be made of oriented strand board, plywood, wood, steel, or concrete. Typically, a beam is bigger than, and is thus distinguished from, a joist. Joists are often supported by beams and are usually repetitive.
The wider the span between the supporting structures, the deeper the joist will need to be if it is not to deflect under load. Lateral support also increases its strength. There are approved formulas for calculating the depth required and reducing the depth as needed; however, a rule of thumb for calculating the depth of a wooden floor joist for a residential property is half the span in feet plus two inches; for example, the joist depth required for a 14-foot span is 9 inches. Many steel joist manufacturers supply load tables in order to allow designers to select the proper joist sizes for their projects.
Engineered wood products such as I-joists gain strength from the depth of the floor or the height of each joist. A common saying in the industry is that deeper is cheaper, referring to the lower quality but often more cost effective joists designed for joist depths of 14 inches or more.
Bandsill is another term for joist used by construction workers and home inspectors in the southeastern United States.
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Dansk (Danish)
n. - gulvbjælke, loftsbjælke, underligger
v. tr. - lave flader med bjælker/underliggere
Français (French)
n. - solive, poutre
v. tr. - mettre des solives
Deutsch (German)
n. - Deckenbalken, Träger
v. - mit Trägern bauen
Ελληνική (Greek)
n. - (οικοδ.) πατόξυλο, δοκάρι, πάτερο
v. - στηρίζω με δοκό
Português (Portuguese)
n. - viga (f), trave (f)
v. - construir com vigas
Русский (Russian)
балка, стропило
Español (Spanish)
n. - vigueta, viga
v. tr. - colocar vigas o viguetas
Svenska (Swedish)
n. - tvärbjälke, golvbjälke, takbjälke
v. - spänna tvärbjälke
中文(简体)(Chinese (Simplified))
托梁, 桁, 为...架搁栏, 为...架拖架
中文(繁體)(Chinese (Traditional))
n. - 托梁, 桁
v. tr. - 為...架擱欄, 為...架拖架
한국어 (Korean)
n. - 장선 , 대들보
v. tr. - 장선을 대다
العربيه (Arabic)
(الاسم) رافدة, كمرة من الصلب (فعل) صلح الرافدة
עברית (Hebrew)
n. - קורת תמיכה מעץ (בבניין)
v. tr. - התקין קורות תומכות
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