Engineered Wood
Kwantlen College, Langley, British Columbia
Increasingly, builders are using engineered wood products such as glulam, LVL, PSL, OSB, plywood, I-joists and I-beams, and roof trusses, for building joists, beams, studs, and window and door frames. Engineered wood products are very stable and offer greater structural strength than typical wood building materials. They can be used for joists and beams that replace steel in many building projects.
Plywood is the original engineered wood product. It is manufactured by gluing together thin veneers of wood. Plywood provides additional insulation, strength and integrity to a structure. It is used to create the skin or sub-surface for wood framed wall/flooring/ roofing assemblies.
Oriented Strand Board (OSB) uses strands of wood fibre bonded together with heat and pressure to create a waterproof sheathing product. Like plywood, OSB is used for wood framed wall/flooring/roofing assemblies.
Glue laminated products (glulam) are structural timber products manufactured by gluing together individual pieces of dimension lumber under controlled conditions. The attributes of this wood product account for its frequent use as an attractive architectural and structural building material. Glulam is used for columns and for beams and frequently for curved members loaded in combined bending and compression.
Laminated Veneer Lumber (LVL) is a layered composite of wood veneers and adhesive. Once it is fabricated into billets of various thickness and widths, it can be cut into stock for headers and beams, flanges for prefabricated wood I-joists, or for other specific uses where high strength, dimension stability, and reliability are required.
Parallel Strand Lumber (PSL) is a strong, consistent material that has a high load carrying ability and is resistant to seasoning stresses. It is well suited for use as beams and columns for post and beam construction, and for beams, headers, and lintels for light framing construction. PSL is an attractive material that is suited to both applications where finished appearance is important and structural applications where appearance is not a factor.
Finger-jointed lumber is made up of short pieces of wood combined to form longer lengths and is used in door jams, mouldings and studs. It is also produced in long lengths and wide dimensions for floors.
I-joists/I-beams are made by gluing solid sawn lumber or laminated veneer lumber (LVL) flanges to a plywood or oriented strandboard (OSB) panel web to produce a dimensionally stable light-weight member. The uniform stiffness, strength, and light weight of these prefabricated structural products makes them well suited for longer span joist and rafter applications for both residential and commercial construction.
Roof trusses are structural frames relying on a triangular arrangement of webs and chords to transfer loads to reaction points. Economy, ease of fabrication, fast delivery and simplified erection procedures make wood trusses competitive in many roof and floor applications. High strength to weight ratios permit long spans offering flexibility in floor layouts by often eliminating the need for interior load bearing walls.