Laminated Strand Lumber
Laminated Strand Lumber (LSL) is one of the more recent structural composite lumber (SCL) products to come into widespread use. LSL provides attributes such as high strength, high stiffness and dimensional stability. The manufacturing process of LSL enables large members to be made from relatively small trees, providing efficient utilization of forest resources. LSL is commonly fabricated using fast growing wood species such as Aspen and Poplar. LSL is used primarily as structural framing for residential, commercial and industrial construction. Common applications of LSL in construction include headers and beams, tall wall studs, rim board, sill plates, millwork and window framing. LSL also offers good fastener-holding strength. Similar to parallel strand lumber (PSL) and oriented strand lumber (OSL), LSL is made from flaked wood strands that have a length-to-thickness ratio of approximately 150. Combined with an adhesive, the strands are oriented and formed into a large mat or billet and pressed. LSL 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 LSL are arranged parallel to the longitudinal axis of the member. LSL 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, LSL 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, LSL 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. LSL is a proprietary product and therefore, the specific engineering properties and sizes are unique to each manufacturer. Thus, LSL 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
Cross-Laminated Timber (CLT)
Cross-laminated timber (CLT) is a proprietary engineered wood product that is prefabricated using several layers of kiln-dried lumber, laid flat-wise, and glued together on their wide faces. Panels typically consist of three, five, seven or nine alternating layers of dimension lumber. The alternating directions of the CLT laminations provide it with high dimensional stability. CLT also has a high strength to weight ratio, along with exhibiting advantages for structural, fire, thermal and acoustic performance. Panel thicknesses usually range between 100 to 300 mm (4 to 12 in), but panels as thick as 500 mm (20 in) can be produced. Panel sizes range from 1.2 to 3 m (4 to 10 ft) in width and 5 to 19.5 m (16 to 64 ft) in length. The maximum panel size is limited by the size of the manufacturer’s press and transportation regulations. The design provisions for CLT in Canada apply to sawn lumber panels manufactured in accordance with the ANSI/APA PRG 320 standard. Typically, all the laminations in one direction are manufactured using the same grade and species of lumber. However, adjacent layers are permitted to be of different thickness and made of alternative grades or species. The moisture content of the lumber laminations at the time of CLT manufacturing is between 9 and 15%. There are five primary CLT stress grades; E1, E2, E3, V1 and V2. Stress grade E1 is the most readily available stress grade. The “E” designation indicates machine stress rated (MSR, or E-rated) lumber and the “V” designation indicates visually graded lumber. Stress grades E1, E2 and E3 consist of MSR lumber in all longitudinal layers and visually graded lumber in the transverse layers, while stress grades V1 and V2 consist of visually graded lumber in both longitudinal and transverse layers. Properties for custom CLT stress grades are also published by individual manufacturers. Similar to other proprietary structural wood products, CLT can be evaluated by the Canadian Construction Materials Centre (CCMC) in order to produce a product evaluation report. Unlike primary and custom CLT stress grades which are associated with structural capacity, appearance grades refer to the surface finish of CLT panels. Any stress grade can usually be produced in any surface finish targeted by the designer. Accommodations for reductions in strength and stiffness due to panel profiling or other face- or edge-finishes must be made. The Appendix of ANSI/APA PRG 320 provides examples of CLT appearance classifications. Structural adhesives used in bonding laminations must comply with CSA O112.10 and ASTM D7247 and are also evaluated for heat performance during exposure to fire. The different classes of structural adhesives that are typically used include: Emulsion polymer isocyanate (EPI); One-component polyurethane (PUR); Phenolic types such as phenol-resorcinol formaldehyde (PRF). Since pressure treatment with water-borne preservatives can negatively affect bond adhesion, CLT is not permitted to be treated with water-borne preservatives after gluing. For CLT treated with fire-retardant or other potentially strength-reducing chemicals, strength and stiffness is required to be based on documented test results. As part of the prefabrication process, CLT panels are cut to size, including door and window openings, with state-of-the art computer numerical controlled (CNC) routers, capable of making complex cuts with low tolerances. Prefabricated CLT elements arrive on site ready for immediate installation. CLT offers design flexibility and low environmental impacts for floor, roof and wall elements within innovative mid-rise and tall wood buildings. For further information on CLT, refer to the following resources: Kalesnikoff Nordic Structures APA – The Engineered Wood Association Canadian Construction Materials Centre (CCMC) Element5 ANSI/APA PRG 320 Standard for Performance-Rated Cross-Laminated Timber CSA O86 Engineering design in wood CSA O112.10 Evaluation of Adhesives for Structural Wood Products (Limited Moisture Exposure) ASTM D7247 Standard Test Method for Evaluating the Shear Strength of Adhesive Bonds in Laminated Wood Products at Elevated Temperatures
Glulam
Glulam (glued-laminated timber) is an engineered structural wood product that consists of multiple individual layers of dimension lumber that are glued together under controlled conditions. All Canadian glulam is manufactured using waterproof adhesives for end jointing and for face bonding and is therefore suitable for both exterior and interior applications. Glulam has high structural capacity and is also an attractive architectural building material. Glulam is commonly used in post and beam, heavy timber and mass timber structures, as well as wood bridges. Glulam is a structural engineered wood product used for headers, beams, girders, purlins, columns, and heavy trusses. Glulam is also manufactured as curved members, which are typically loaded in combined bending and compression. It can also be shaped to create pitched tapered beams and a variety of load bearing arch and trusses configurations. Glulam is often employed where the structural members are left exposed as an architectural feature. Available sizes of glulam Standard sizes have been developed for Canadian glued-laminated timber to allow optimum utilization of lumber which are multiples of the dimensions of the lamstock used for glulam manufacture. Suitable for most applications, standard sizes offer the designer economy and fast delivery. Other non-standard dimensions may be specially ordered at additional cost because of the extra trimming required to produce non-standard sizes. The standard widths and depths of glulam are shown in Table 6.7, below. The depth of glulam is a function of the number of laminations multiplied by the lamination thickness. For economy, 38 mm laminations are used wherever possible, and 19 mm laminations are used where greater degrees of curvature are required. Standard widths of glulam Standard finished widths of glulam members and common widths of the laminating stock they are made from are given in Table 4 below. Single widths of stock are used for the complete width dimension for members less than 275 mm (10-7/8″) wide. However, members wider than 175 mm (6-7/8″) may consist of two boards laid side by side. All members wider than 275 mm (10-7/8″) are made from two pieces of lumber placed side by side, with edge joints staggered within the depth of the member. Members wider than 365 mm (14-1/4″) are manufactured in 50 mm (2″) width increments, but will be more expensive than standard widths. Manufacturers should be consulted for advice. Initial width of glulam stock Finished width of glulam stock mm. in. mm. in. 89 3-1/2 80 3 140 5-1/2 130 5 184 7-1/4 175 6-7/8 235 (or 89 + 140) 9-1/4 (or 3-1/2 + 5-1/2) 225 (or 215) 8-7/8 (or 8-1/2) 286 (or 89 + 184) 11-1/4 (or 3-1/2 + 7-1/4) 275 (or 265) 10-7/8 (or 10-1/4) 140 + 184 5-1/2 + 7-1/4 315 12-1/4 140 + 235 5-1/2 + 9-1/4 365 14-1/4 Notes: Members wider than 365 mm (14-1/4″) are available in 50 mm (2″) increments but require a special order. Members wider than 175 mm (6-7/8″) may consist of two boards laid side by side with logitudinal joints staggered in adjacent laminations. Standard depths of glulam Standard depths for glulam members range from 114 mm (4-1/2″) to 2128 mm (7′) or more in increments of 38 mm (1-1/2″) and l9 mm (3/4″). A member made from 38 mm (1-1/2″) laminations costs significantly less than an equivalent member made from l9 mm (3/4″) laminations. However, the l9 mm (3/4″) laminations allow for a greater amount of curvature than do the 38 mm (1-1/2″) laminations. Width in. Depth range mm in. 80 3 114 to 570 4-1/2 to 22-1/2 130 5 152 to 950 6 to 37-1/2 175 6-7/8 190 to 1254 7-1/2 to 49-1/2 215 8-1/2 266 to 1596 10-1/2 to 62-3/4 265 10-1/4 342 to 1976 13-1/2 to 77-3/4 315 12-1/4 380 to 2128 15 to 83-3/4 365 14-1/4 380 to 2128 15 to 83-3/4 Note: 1. Intermediate depths are multiples of the lamination thickness, which is 38 mm (1-1/2″ nom.) except for some curved members that require 19 mm (3/4″ nom.) laminations. Laminating stock may be end jointed into lengths of up to 40 m (130′) but the practical limitation may depend on transportation clearance restrictions. Therefore, shipping restrictions for a given region should be determined before specifying length, width or shipping height. Glulam appearance grades In specifying Canadian glulam products, it is necessary to indicate both the stress grade and the appearance grade required. The appearance of glulam is determined by the degree of finish work done after laminating and not by the appearance of the individual lamination pieces. Glulam is available in the following appearance grades: Industrial Commercial Quality The appearance grade defines the amount of patching and finishing work done to the exposed surfaces after laminating (Table 6.8) and has no strength implications. Quality grade provides the greatest degree of finishing and is intended for applications where appearance is important. Industrial grade has the least amount of finishing. Grade Description Industrial Grade Intended for use where appearance is not a primary concern such as in industrial buildings; laminating stock may contain natural characteristics allowed for specified stress grade; sides planed to specified dimensions but occasional misses and rough spots allowed; may have broken knots, knot holes, torn grain, checks, wane and other irregularities on surface. Commercial Grade Intended for painted or flat-gloss varnished surfaces; laminating stock may contain natural characteristics allowed for specified stress grade; sides planed to specified dimensions and all squeezed-out glue removed from surface; knot holes, loose knots, voids, wane or pitch pockets are not replaced by wood inserts or filler on exposed surface. Quality Grade Intended for high-gloss transparent or polished surfaces, displays natural beauty of wood for best aesthetic appeal; laminating stock may contain natural characteristics allowed for specified stress grade; sides planed to specified dimensions and all squeezed-out glue removed from surface; may have tight knots, firm heart stain and medium sap stain on sides; slightly broken or split knots, slivers, torn grain or checks on surface filled; loose knots, knot holes, wane and pitch pockets removed and replaced with non-shrinking
Fire Code
National Fire Code of Canada The National Building Code of Canada (NBC) and the National Fire Code of Canada (NFC), both published by the National Research Council of Canada (NRC) and developed by the Canadian Commission on Building and Fire Codes (CCBFC), are developed as companion documents. The NBC establishes minimum standards for the health and safety of the occupants of new buildings. It also applies to the alteration of existing buildings, including changes in occupancy. The NBC is not retroactive. That is, a building constructed in conformance with a particular edition of the NBC, which is in effect at the time of its construction, is not automatically required to conform to the subsequent edition of the NBC. That building would only be required to conform to an updated version of the NBC if it were to undergo a change in occupancy or alterations which invoke the application of the new NBC in effect at the time of the change in occupancy or major alteration. The NFC addresses fire safety during the operation of facilities and buildings. The requirements in the NFC, on the other hand, are intended to ensure the level of safety initially provided by the NBC is maintained. With this objective, the NFC regulates: the conduct of activities causing fire hazards the maintenance of fire safety equipment and egress facilities limitations on building content, including the storage and handling of hazardous products the establishment of fire safety plans The NFC is intended to be retroactive with respect to fire alarm, standpipe and sprinkler systems. In 1990, the NFC was revised to clarify that such systems “shall be provided in all buildings where required by and in conformance with the requirements of the National Building Code of Canada.” This ensures that buildings are adequately protected against the inherent risk at the same level as the NBC would require for a new building. It does not concern other fire protection features such as smoke control measures or firefighter’s elevators. The NFC also ensures that changes in building use do not increase the risk beyond the limits of the original fire protection systems. The NBC and the NFC are written to minimize the possibility of conflict in their respective contents. Both must be considered when constructing, renovating or maintaining buildings. They are complementary, in that the NFC takes over from the NBC once the building is in operation. In addition, older structures which do not conform to the most current level of fire safety can be made safer through the requirements of the NFC. The most recent significant changes in the NFC relate the construction of six-storey buildings using combustible construction. As a result, eight additional protection measures related to mid-rise combustible buildings have been added to address fire hazards during construction when fire protection features are not yet in place.
Energy Code
The National Energy Code of Canada for Buildings (NECB) aims to help save on energy bills, reduce peak energy demand, and improve the quality and comfort of the building’s indoor environment. Through each code development cycle, the NECB intends to implement a tiered approach toward Canada’s goal for new buildings, as presented in the “Pan-Canadian Framework on Clean Growth and Climate Change”, of achieving ‘Net Zero Energy Ready’ buildings by 2030. The NECB is available for free online; published by the National Research Council (NRC) and developed by the Canadian Commission on Building and Fire Codes in collaboration with Natural Resources Canada (NRCan). CWC maintains ongoing participation in the development and updating of the NECB. The NECB sets out technical requirements for energy efficient design and construction and outlines the minimum energy efficiency levels for code compliance of all new buildings. The NECB applies to all building types, except housing and small buildings, which are addressed under Clause 9.36 of the National Building Code of Canada. The NECB offers three compliance paths: prescriptive, trade-off and performance. The most cost-effective time to incorporate energy efficiency measures into a building is during the initial design and construction phase. It is much more expensive to retrofit later. This is particularly true for the building envelope, which includes exterior walls, windows, doors and roofing. The NECB addresses considerations such as air infiltration rates (air leakage) and thermal transmission of heat through the building envelope. Considering the different climate zones in Canada, the NECB also provides requirements related to maximum overall (effective) thermal transmittance for above-ground opaque wall assemblies and effective thermal resistance of assemblies in contact with ground, e.g., permanent wood foundations. In addition, the NECB specifies the maximum fenestration and door to wall ratio based on the climate zone in which the building in located. As energy efficiency requirements for buildings are increased, wood is a natural solution to pair with other insulating and weatherizing materials to develop buildings with high operational energy performance and provide consistent indoor comfort for occupants. For further information on the NECB, visit the Codes Canada at the National Research Council Canada.
Combustible construction
The provision of fire safety in a building is a complex matter; far more complex than the relative combustibility of the main structural materials used in a building. To develop safe code provisions, prevention, suppression, movement of occupants, mobility of occupants, building use, and fuel control are but a few of the factors that must be considered in addition to the combustibility of the structural components. Fire-loss experience shows that building contents play a large role in terms of fuel load and smoke generation potential in a fire. The passive fire protection provided by the fire-resistance ratings on the floor and wall assemblies in a building assures structural stability in a fire. However, the fire-resistance rating of the structural assemblies does not necessarily control the movement of smoke and heat, which can have a large impact on the level of safety and property damage resulting from fire. The National Building Code of Canada (NBC) categorizes wood buildings as ‘combustible construction’. Despite being termed combustible, common construction techniques can give wood frame construction fire-resistance ratings up to two hours. When designed and built to code requirements, wood buildings provide the same level of life safety and property protection required for comparably sized buildings defined under the NBC as ‘noncombustible construction’. Wood has been used for virtually all types of buildings, including; schools, warehouses, fire stations, apartment buildings, and research facilities. The NBC sets out guidelines for the use of wood in applications that extend well beyond the traditional residential and small building sector. The NBC allows wood construction of up to six storeys in height, and wood cladding for buildings designated to be of noncombustible construction. When meeting the area and height limits for the various NBC building categories, wood frame construction can meet the life safety requirements by making use of wood-frame assemblies (usually protected by gypsum wallboard) that are tested for fire-resistance ratings. The allowable height and area restrictions can be extended by using fire walls to break a large building area into smaller separate building areas. The recognized positive contribution to both life safety and property protection which comes from the use of automatic sprinkler systems can also be used to increase the permissible area of wood buildings. Sprinklers typically operate very early in a fire thereby quickly controlling the damaging effects. For this reason, the provision of automatic sprinkler protection within a building greatly improves the life safety and property protection prospects of all buildings including those constructed of noncombustible materials. The NBC permits the use of ‘heavy timber construction’ in buildings where combustible construction is required to have a 45-minute fire-resistance rating. This form of heavy timber construction is also permitted to be used in large noncombustible buildings in certain occupancies. To be acceptable, the components must comply with minimum dimension and installation requirements. Heavy timber construction is afforded this recognition because of its performance record under actual fire exposure and its acceptance as a fire-safe method of construction. In sprinklered buildings permitted to be of combustible construction, no fire-resistance rating is required for the roof assembly or its supports when constructed from heavy timber. In these cases, a heavy timber roof assembly and its supports would not have to conform to the minimum member dimensions stipulated in the NBC. Mass timber elements may also be used whenever combustible construction is permitted. In those instances, however, such mass timber elements need to be specifically designed to meet any required fire-resistance ratings. NBC definitions: Combustible means that a material fails to meet the acceptance criteria of CAN/ULC-S114, “Test for Determination of Non-Combustibility in Building Materials.” Combustible construction means that type of construction that does not meet the requirements for noncombustible construction. Heavy timber construction means that type of combustible construction in which a degree of fire safety is attained by placing limitations on the sizes of wood structural members and on thickness and composition of wood floors and roofs and by the avoidance of concealed spaces under floors and roofs. Noncombustible construction means that type of construction in which a degree of fire safety is attained by the use of noncombustible materials for structural members and other building assemblies. Noncombustible means that a material meets the acceptance criteria of CAN/ULC-S114, “Test for Determination of Non-Combustibility in Building Materials.” For further information, refer to the following resources: National Building Code of Canada CAN/ULC-S114 Test for Determination of Non-Combustibility in Building Materials Wood Design Manual 2017
Encapsulated mass timber construction
In addition to combustible, heavy timber and noncombustible construction, a new construction type is presently being considered for inclusion into the National Building Code of Canada (NBC). Encapsulated mass timber construction (EMTC) is proposed to be defined as the “type of construction in which a degree of fire safety is attained by the use of encapsulated mass timber elements with an encapsulation rating and minimum dimensions for the structural timber members and other building assemblies.” EMTC is neither ‘combustible construction’ nor ‘heavy timber construction’ nor ‘noncombustible construction’, as defined within the NBC. EMTC is required to have an encapsulation rating. The encapsulation rating is the time, in minutes, that a material or assembly of materials will delay the ignition and combustion of encapsulated mass timber elements when it is exposed to fire under specified conditions of test and performance criteria, or as otherwise prescribed by the NBC. The encapsulation rating for EMTC is determined through the ULC S146 test method. In order for structural wood elements to be considered ‘mass timber’, they must meet minimum size requirements, which are different for horizontal (walls, floors, roofs, beams) and vertical (columns, arches) load-bearing elements and dependent on the number of sides that the element is exposed to fire. EMTC construction in Canada is expected to be limited to a height of twelve-storeys, that is, the uppermost floor level may be a maximum of 42 m (137 ft) above the first floor. An EMTC building must be sprinklered throughout according to NFPA 13 and it is likely that some mass timber will also be able to be exposed in the suites. All EMTC elements are expected to have a minimum two-hour fire resistance rating and the building floor area to be limited to 6,000 m2 for Group C occupancy and 7,200 m2 for Group D occupancy. There are restrictions on the use of exterior cladding elements in EMTC, as well as other restrictions on the use of; combustible roofing materials, combustible window sashes and frames, combustible components in exterior walls, nailing elements, combustible flooring elements, combustible stairs, combustible interior finishes, combustible elements in partitions, and concealed spaces. If any encapsulation material is damaged or removed, it will be required to be repaired or replaced so that the encapsulation rating of the materials is maintained. Additionally, requirements related to construction site fire safety are to be applied to construction access, standpipe installation and protective encapsulation. EMTC and its related provisions are anticipated to be included in the NBC 2020. NBC definitions: Combustible means that a material fails to meet the acceptance criteria of CAN/ULC-S114, “Test for Determination of Non-Combustibility in Building Materials.” Combustible construction means that type of construction that does not meet the requirements for noncombustible construction. Heavy timber construction means that type of combustible construction in which a degree of fire safety is attained by placing limitations on the sizes of wood structural members and on thickness and composition of wood floors and roofs and by the avoidance of concealed spaces under floors and roofs. Noncombustible construction means that type of construction in which a degree of fire safety is attained by the use of noncombustible materials for structural members and other building assemblies. Noncombustible means that a material meets the acceptance criteria of CAN/ULC-S114, “Test for Determination of Non-Combustibility in Building Materials.” For further information, refer to the following resources: Guide to Encapsulated Mass Timber Construction in the Ontario Building Code ULC S146 Standard Method of Test for the Evaluation of Encapsulation Materials and Assemblies of Materials for the Protection of Mass Timber Structural Members and Assemblies Fire performance of mass-timber encapsulation methods and the effect of encapsulation on char rate of cross-laminated timber (Hasburgh et al., 2016) CAN/ULC-S114 Test for Determination of Non-Combustibility in Building Materials NFPA 13 Standard for the Installation of Sprinkler Systems
Acoustics
Wood is composed of many small cellular tubes that are predominantly filled with air. The natural composition of the material allows for wood to act as an effective acoustical insulator and provides it with the ability to dampen vibrations. These sound-dampening characteristics allow for wood construction elements to be specified where sound insulation or amplification is required, such as libraries and auditoriums. Another important acoustical property of wood is its ability to limit impact noise transmission, an issue commonly associated with harder, more dense materials and construction systems. The use of topping or a built-up floating floor system overlaid on light wood frame or mass timber structural elements is a common approach to address acoustic separation between floors of a building. Depending on the type of materials in the built-up floor system, the topping can be applied directly to the wood structural members or over top of a moisture barrier or resilient layer. The use of gypsum board, absorptive (batt/loose-fill) insulation and resilient channels are also critical components of a wood-frame wall or floor assembly that also contribute to the acoustical performance of the overall assembly. Acoustic design considers a number of factors, including building location and orientation, as well as the insulation or separation of noise-producing functions and building elements. Sound Transmission Class (STC), Apparent Sound Transmission Class (ASTC) and Impact Insulation Class (IIC) ratings are used to establish the level of acoustic performance of building products and systems. The different ratings can be determined on the basis of standardized laboratory testing or, in the case of ASTC ratings, calculated using methodologies described in the NBC. Currently, the National Building Code of Canada (NBC) only regulates the acoustical design of interior wall and floor assemblies that separate dwelling units (e.g. apartments, houses, hotel rooms) from other units or other spaces in a building. The STC rating requirements for interior wall and floor assemblies are intended to limit the transmission of airborne noise between spaces. The NBC does not mandate any requirements for the control of impact noise transmission through floor assemblies. Footsteps and other impacts can cause severe annoyance in multifamily residences. Builders concerned about quality and reducing occupant complaints will ensure that floors are designed to minimize impact transmission. Beyond conforming to the minimum requirements of the NBC in residential occupancies, designers can also establish acoustic ratings for design of non-residential projects and specify materials and systems to ensure the building performs at that level. In addition to limiting transmission of airborne noise through internal structural walls and floors, flanking transmission of sound through perimeter joints and sound transmission through non-structural partition walls should also be considered during the acoustical design. Further information and requirements related to STC, ASTC and IIC ratings are provided in Appendix A of the NBC in sections A-9.10.3.1. and A-9.11.. This includes, inter alia, Tables 9.10.3.1-A and 9.10.3.1.-B that provide generic data on the STC ratings of different types of wood stud walls and STC and IIC ratings for different types of wood floor assemblies, respectively. Tables A-9.11.1.4.-A to A-9.11.1.4.-D present generic options for the design and construction of junctions between separating and flanking assemblies. Constructing according to these options is likely to meet or exceed an ASTC rating of 47 that is mandated by the NBC. Table A-Table 9.11.1.4. presents data about generic floor treatments that can be used to improve the flanking sound insulation performance of lightweight framed floors, i.e., additional layers of material over the subfloor (e.g. concrete topping, OSB or plywood) and finished flooring or coverings (e.g., carpet, engineered wood).
2024 Catherine Lalonde Memorial Scholarships Celebrate Students Driving Innovation in the Wood Industry
Ottawa, ON, December 12, 2024 – The Canadian Wood Council (CWC) announced the recipients of the 2024 Catherine Lalonde Memorial Scholarships: Laura Walters (McMaster University) and Jiawen Shen (University of British Columbia). Both students were recognized for their academic excellence and impactful research projects in the structural wood products industry. Established nineteen years ago, the memorial scholarships are awarded each year to graduate students whose wood research exemplifies the same level of passion for wood and the wood products industry that Catherine Lalonde tirelessly demonstrated as a professional engineer and president of the CWC. Laura Walters Laura is a 3rd-year graduate student pursuing a Master of Applied Science in Civil Engineering under a joint collaboration between McMaster University and the University of Northern British Columbia (UNBC). Her research project explores the use of pre-engineered beam hangers in mass timber post-and-beam systems, with a focus on the implications of design and modelling assumptions on the evaluation of structural load paths. Her work provides valuable insights into the design considerations and assumptions required for more accurate and reliable design of mass timber columns when pre-engineered beam hangers are used. Jiawen Shen Jiawen is a 1st year graduate student pursuing a Master in Wood Science at the University of British Columbia. Her research project focuses on the development of binderless composite bark-board cladding and insulation panels that are durable, ignition resistant, carbon neutral, and manufactured from an underutilized by-product that would otherwise be burned, landfilled, or used for low-value purposes. Collaborating with a Vancouver-based architecture firm on this project, her work is key to advancing the commercial application of these innovative cladding products. “This year marks a historic milestone for the Catherine Lalonde Memorial Scholarship program as, for the first time, it is awarded to two exceptional women,” said Martin Richard, VP of Market Development and Communications at the CWC. “Their achievements highlight the outstanding talent driving innovation in wood research and construction. We are inspired by their contributions and the growing diversity shaping the future of wood-based solutions.”
