What is an engineered joist? In architecture and engineering, a joist is one of the horizontal supporting members that run between foundations, walls, or beams to support a ceiling or floor. Typically, a joist has the cross section of a plank. Joists are often supported by beams laid out in repetitive patterns. Grandor Lumber has an extensive selection of Ottawa Engineered Joists. Our mission is to be the best provider of sustainable wood solutions to the building industry. Our values and commitment to environment, employees, customers and innovation define our operating principles. Nordic Engineered Wood offers a complete line of residential and commercial products for various construction applications. With the largest team of technical and sales support associates in Canada, Weyerhaeuser is the industry leader in engineered wood products, helping Canadian dealers, builders and design professionals achieve superior results in the light commercial, multi-family and single-family construction industry.