Sometimes referred to as I-beams, are structural, load-carrying products. I-joists are typically available in long lengths and because they are very lightweight can be easily handled at the jobsite without the need for costly handling equipment. Their "I" configuration provides high bending strength and stiffness characteristics. The top and bottom flange material for I-joists is typically dimension lumber or laminated veneer lumber; the web material is OSB or plywood. Prefabricated wood I-joists are used extensively in residential construction for both floor and roof framing and are among the fastest growing of the glued engineered wood products.