Oakville Fire Station 8
Ontario Mid-Rise Reference Guide
Ontario Mid-Rise Reference Guide
Ontario Tall Wood Reference Guide
ONTARIO WOOD BRIDGE REFERENCE GUIDE
Ontario Wood Bridge Reference Guide

Ontario Wood Bridge Reference Guide
Operations Centre – Gulf Islands National Park Reserve
Operations Centre (Gulf Islands National Park Reserve)
Oriented Strand Board (OSB)

Oriented Strand Board (OSB) is a widely used, versatile structural wood panel. OSB makes efficient use of forest resources, by employing less valuable, fast-growing species. OSB is made from abundant, small diameter poplar and aspen trees to produce an economical structural panel. The manufacturing process can make use of crooked, knotty and deformed trees which would not otherwise have commercial value, thereby maximizing forest utilization. OSB has the ability to provide structural performance advantages, an important component of the building envelope and cost savings. OSB is a dimensionally stable wood-based panel that has the ability to resist delamination and warping. OSB can also resist racking and shape distortion when subjected to wind and seismic loadings. OSB panels are light in weight and easy to handle and install. OSB panels are primarily used in dry service conditions as roof, wall and floor sheathing, and act as key structural components for resisting lateral loads in diaphragms and shearwalls. OSB is also used as the web material for some types of prefabricated wood I-joists and the skin material for structural insulated panels. OSB can also be used in siding, soffit, floor underlayment and subfloor applications. Some specialty OSB products are made for siding and for concrete formwork, although OSB is not commonly treated using preservatives. OSB has many interleaved layers which provide the panel with good nail and screw holding properties. Fasteners can be driven as close as 6 mm (1/4 in) from the panel edge without risk of splitting or breaking out. OSB is a structural mat-formed panel product that is made from thin strands of aspen or poplar, sliced from small diameter roundwood logs or blocks, and bonded together with a waterproof phenolic adhesive that is cured under heat and pressure. OSB is also manufactured using the southern yellow pine species in the United States. Other species, such as birch, maple or sweetgum can also be used in limited quantities during manufacture. OSB is manufactured with the surface layer strands aligned in the long panel direction, while the inner layers have random or cross alignment. Similar to plywood, OSB is stronger along the long axis compared to the narrow axis. This random or cross orientation of the strands and wafers results in a structural engineered wood panel with consistent stiffness and strength properties, as well as dimensional stability. It is also possible to produce directionally-specific strength properties by adjusting the orientation of strand or wafer layers. The wafers or strands used in the manufacture of OSB are generally up to 150 mm (6 in) long in the grain direction, 25 mm (1 in) wide and less than 1 mm (1/32″) in thickness. In Canada, OSB panels are manufactured to meet the requirements of the CSA O325 standard. This standard sets performance ratings for specific end uses such as floor, roof and wall sheathing in light-frame wood construction. Sheathing conforming to CSA O325 is referenced in Part 9 of the National Building Code of Canada (NBC). In addition, design values for OSB construction sheathing are listed in CSA O86, allowing for engineering design of roof sheathing, wall sheathing and floor sheathing using OSB conforming to CSA O325. OSB panels are manufactured in both imperial and metric sizes, and are either square-edged or tongue-and-grooved on the long edges for panels 15 mm (19/32 in) and thicker. For more information on available sizes of OSB panel, refer to the document below. For more information on OSB, please refer to the following resources: APA – The Engineered Wood Association National Building Code of Canada CSA O86 Engineering design in wood CSA O325 Construction sheathing CSA O437 Standards on OSB and Waferboard PFS TECO Example specifications for oriented strand board (OSB) Oriented Strand Board (OSB) Grades Oriented Strand Board (OSB) Manufacture Oriented Strand Board (OSB) Quality Control Oriented Strand Board (OSB) Sizes Oriented Strand Board (OSB) Storage and Handling
Oriented Strand Lumber

Oriented Strand Lumber (OSL) Oriented Strand Lumber (OSL) provides attributes such as high strength, high stiffness and dimensional stability. The manufacturing process of OSL enables large members to be made from relatively small trees, providing efficient utilization of forest resources. OSL is used primarily as structural framing for residential, commercial and industrial construction. Common applications of OSL in construction include headers and beams, tall wall studs, rim board, sill plates, millwork and window framing. OSL also offers good fastener-holding strength. Similar to laminated strand lumber (LSL), OSL is made from flaked wood strands that have a length-to-thickness ratio of approximately 75. The wood strands used in OSL are shorter than those in LSL. Combined with an adhesive, the strands are oriented and formed into a large mat or billet and pressed. OSL resembles oriented strand board (OSB) in appearance as they are both fabricated from the similar wood species and contain flaked wood strands, however, unlike OSB, the strands in OSL are arranged parallel to the longitudinal axis of the member. OSL is a solid, highly predictable, uniform engineered wood product due to the fact that natural defects such as knots, slope of grain and splits have been dispersed throughout the material or have been removed altogether during the manufacturing process. Like other SCL products such as LVL and PSL, OSL offers predictable strength and stiffness properties and dimensional stability that minimize twist and shrinkage. All special cutting, notching or drilling should be done in accordance with manufacturer’s recommendations. Manufacturer’s catalogues and evaluation reports are the primary sources of information for design, typical installation details and performance characteristics. As with any other wood product, OSL should be protected from the weather during jobsite storage and after installation. Wrapping of the product for shipment to the job site is important in providing moisture protection. End and edge sealing of the product will enhance its resistance to moisture penetration. OSL is a proprietary product and therefore, the specific engineering properties and sizes are unique to each manufacturer. Thus, OSL does not have a common standard of production and common design values. Design values are derived from test results analysed in accordance with CSA O86 and ASTM D5456 and the design values are reviewed and approved by the Canadian Construction Materials Centre (CCMC). Products meeting the CCMC guidelines receive an Evaluation Number and Evaluation Report that includes the specified design strengths, which are subsequently listed in CCMC’s Registry of Product Evaluations. The manufacturer’s name or product identification and the stress grade is marked on the material at various intervals, but due to end cutting it may not be present on every piece. For further information, refer to the following resources: APA – The Engineered Wood Association Canadian Construction Materials Centre (CCMC), Institute for Research in Construction CSA O86 Engineering design in wood ASTM D5456 Standard Specification for Evaluation of Structural Composite Lumber Products