I-Joist
An I-Joist is a wood-based material beam whose cross-sectional shape (I-cross section) consists of flanges and webs. This eliminates problems that exist with conventional wooden planks (with a rectangular cross-section), such as deflection or warpage. The I- shaped cross-section is known from steel construction (see IPE profile ) and offers the advantage that large bending moments can be transmitted. Most of the compressive and tensile stresses are dissipated via the flanges, which is why solid wood is used for I-Joists due to its good resistance to the wood fiber direction . The shear stresses , which act perpendicular to the direction of the wood grain, are far more difficult to transmit from solid wood, which is why the web of an I-Joist that is subjected to shear loads i. d. Usually made of a wood material ( chipboard or OSB panels ).
This means that I-Joists have a significantly lower dead weight than massive solid wood planks with significantly more advantageous and higher load capacity.
In Germany, wooden beams with an I-cross section are often used for shuttering systems in reinforced concrete ceilings. The low dead weight combined with high resistance to stress and low deformation under high loads makes these components ideal for this application.