I-joists are strong, lightweight, “I” shaped engineered wood structural members that meet demanding performance standards. I-joists are comprised of top and bottom flanges, which resist bending, united with webs, which provide outstanding shear resistance. The flange material is typically laminated veneer lumber (LVL) or solid sawn lumber, and the web is made with plywood or OSB. The robust combination of structural characteristics results in a versatile, economical framing member that is easy to install in residential and light commercial projects. (https://www.apawood.org/i-joist)
I-joists are used extensively in residential floor and roof framing. They are ideal for long spans, including continuous spans over intermediate supports. Because I-joists are straight and true, it’s easier for builders to avoid crowning and maintain a level framing surface. In addition, wood I-joists are typically stocked and readily available in depths that meet the needs of residential framing. (https://www.apawood.org/i-joist)
PWI-joists are a balanced product and do not have a top or bottom like an unbalanced glulam. However, the web does have pre-punched knock-outs that are closer to one flange. The knock-outs are easier for electricians to use when located near the bottom of the installed joist.
PWLVL billets, originally 48” wide when manufactured, are ripped into narrower widths, typically from 3-1/2” up to 24”, across the 48” wide width. Each piece is the same grade as the original billet. A 1-3/4” x 24” can be ripped to a narrower width, including 18”. The capacity of the new beam would be based on the new size. An 1-3/4” x 18” 2.0E LVL ripped from a 24” beam would have the same design values as one that came straight from the factory in that size. PWLVL cannot, however, be planed or sawn to reduce thickness.
PWLVL, produced for the North American market, has a wax coating applied to mitigate the rate of moisture absorption during storage and construction. This coating will likely make it difficult to apply paint or spray foam insulation directly on the LVL. PWT’s coatings supplier suggests that it would be best to discuss options with the paint supplier for a primer (likely solvent-based) to improve applicability. Inform the paint supplier that the coating contains paraffin wax (hydrocarbon/synthetic wax).
Pacific Woodtech Laminated Veneer Lumber (PWLVL) is produced to specific tolerances based on manufacturing equipment capabilities. Due to the manufacturing processes there may be slight variations between the product and nominal dimensions. This slight deviation in dimensions is called tolerance. When PWLVL leaves the manufacturing facility, its dimension tolerances are within the manufacturer’s limits and the product moisture content is between 6-10%.
PWLVL may swell, shrink, and change shape in response to moisture and adverse weather, even with the additional protection of factory applied sealants. Moisture content for in service conditions will vary widely.
PWLVL products should be protected by keeping the products wrapped, off the ground, stacked, and supported appropriately. Using these guidelines will help keep product clean, shed rain, and promote air circulation to dry off any incidental moisture.
For additional storage and handling information, see: E705 Proper Storage and Handling of IJoists and LVL