A wooden I-joist is a prefabricated beam with an I-shaped cross-section: two horizontal flanges connected by a thin vertical web. The flanges are usually made of laminated veneer lumber (LVL) or solid wood; the web is usually made of OSB or plywood.
How it works
The I-shape places most of the material in the flanges, where the greatest stresses occur during bending. This results in a light, stiff and material-efficient beam.
Advantages
- Available in long lengths
- Straight and dimensionally stable
- Little shrinkage or warping
- Light in weight (easy installation)
- Suitable for large spans
Application
- Floor joists
- Roof joists
- Especially in timber frame construction
Related terms
- I-section
- Timber frame construction
- Beam
- Joist
- Plywood
- OSB
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