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FLOOR JOISTS
Are horizontal structural members used in building construction that support the floor loads and transfer them to vertical members such as walls or beams. They're a crucial part of the framework of a floor system.
Key characteristics
* Material: Typically made from wood (like dimensional lumber or engineered wood such as I-joists or LVL), steel, or concrete.​
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* Spacing: Commonly spaced 16" or 24" apart (on center), depending on load requirements and the type of flooring above.
* Orientation: Run parallel across a space and are supported at the ends by beams, walls, or ledgers.
* Load-bearing: Designed to carry the weight of the floor system including furniture, people, and the flooring materials.
Common Types
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Solid Sawn Lumber – Traditional joists like 2x8, 2x10, or 2x12.
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I-Joists – Engineered wood joists shaped like the letter “I,” known for spanning longer distances with less material.
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Open Web Trusses – Often used for easy mechanical installations (plumbing, HVAC).
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Steel Joists – Used in commercial or industrial buildings for strength and fire resistance.
Installation Considerations
​* Span: Depends on joist size, spacing, and the wood species or material.​
* Bridging or Blocking: Often used between joists to reduce twisting and help distribute loads
.​​* Deflection: Joists must be stiff enough to avoid noticeable bouncing or sagging.
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