n collaboration avec l’Université de Victoria, on a mis au point un mur de cisaillement à haute capacité comportant deux rangées de clous au périmètre du revêtement. On a mené un programme d’essais pour évaluer la performance du mur de cisaillement proposé, ce qui comprend la résistance aux charges latérales et aux déplacements, le comportement hystérétique, la rigidité et la ductilité.
La présente InfoNote décrit brièvement les systèmes de résistance aux forces sismiques (SRFS) en bois massif qui seront inclus dans l’édition 2020 du Code national du bâtiment (CNB) du Canada, leurs limites de hauteur et les principales exigences de conception selon la norme Règles de calcul des charpentes en bois de l’Association canadienne de normalisation CSA O86-19. Elle explique aussi les différences de limite de hauteur entre les différents systèmes de résistance aux charges de gravité et aux charges latérales.
La présente InfoNote décrit brièvement les SRFS en bois massif prometteurs, de même que les modèles analytiques et par éléments finis correspondants dans le but d’encourager leur adoption par les entreprises de conception structurale.
The widespread availability of genomics data and molecular tools for pathogen detection and identification provides scientists and regulators a powerful toolbox for pathogen monitoring. However, this raises questions and concerns regarding the use of these tools in import and export of forest commodities. Discussions around implementation and standardization have highlighted knowledge gaps around their efficacy and suitability in wood and their applicability to forest commodities. This study compared detection efficacy of various emerging tools on artificially infected forest and wood commodities, focusing on Phytophthora pathogens, an important group of invasive and sometimes difficult to detect species. In situ detection was more sensitive than traditional isolation, and for some methods, 100% of infected samples were positive. Detection efficacy varied by tissue type and detection method. The data generated from this study is important in addressing knowledge gaps around pathogen detection in wood.
Nail-laminated timber (NLT) is a large built-up member often used as interior structural members for floors, roofs, walls, and elevator/stair shafts. Because prolonged wetting of wood may cause staining, mould, excessive dimensional change
(sometimes enough to fail fasteners), and even result in decay and loss of strength, construction moisture is an important consideration when building with NLT. This document aims to provide technical information to help architects, engineers, and builders assess the potential for wetting of NLT during building construction and identify appropriate actions to mitigate the risks.
Le bois lamellé-cloué (NLT – Nail-laminated Timber) est un élément massif composé de bois de sciage souvent utilisé comme élément de structure intérieur pour les planchers, les toits, les murs et les cages d'ascenseur/escalier. Étant donné que l’humidification prolongée du bois peut provoquer des taches, de la moisissure, des variations dimensionnelles excessives (parfois suffisantes pour provoquer la défaillance des attaches), et même la pourriture et la perte de résistance, l'humidité est un facteur important à prendre en compte lors de travaux de construction avec du bois lamellé-cloué. Le présent document vise à fournir de l’information technique pouvant aider les architectes, les ingénieurs et les constructeurs à évaluer les risques d’humidification du bois lamellé-cloué pendant la construction de bâtiments et à prendre les mesures appropriées pour atténuer ces risques.
A test program was conducted to generate hygrothermal performance data for light-wood-frame exterior walls meeting the R22 effective (RSI 3.85) requirement for buildings up to six storeys in the City of Vancouver. Six types of exterior wall assemblies, with 12 wall panels in total, were tested using a test hut located in the rear yard of FPInnovations’ Vancouver aboratory. This document provides a brief summary of the test and performance of these walls based on the data collected over the 19 months’ period from October 2018 to May 2020
Un programme d’essais a été réalisé en vue de générer des données sur le rendement hygrothermique des murs à ossature légère de bois qui répondent à l’exigence R22 (RSI 3,85) pour les bâtiments d'au plus six étages à Vancouver. Six types d’assemblage de mur extérieur, avec un total de 12 murs extérieurs, ont été mis à l’essai à l’aide d’une hutte d’essai située dans la cour arrière du laboratoire de FPInnovations à Vancouver. Le présent document présente un court résumé de l’essai et du rendement de ces murs en se basant sur les données recueillies sur une période de 19 mois, soit d’octobre 2018 à mai 2020 (Wang 2021).
Large volumes of forest products are traded internationally. With this comes an increased risk of moving forest pathogens associated with these products. To protect both forest health and international trade, prevention or control of pest movement and establishment needs to be done using approaches which result in minimal trade interruption. Rapid, economical, and accurate detection, identification and risk assessment of pathogens is one of the key aspects of successful management. Significant developments in the last two decades in genomics has enabled more accurate and rapid detection of pathogens. However, many of these techniques have not been thoroughly tested in wood and lack associated standards governing their use in a regulatory setting. There are ongoing concerns that these new methods will add regulatory compliance costs to industry and other stakeholders, or that they will be used improperly and unduly limit market access. To address these concerns, it is critical that the capabilities and limits of these tools are well understood by both industry and international regulators, and that standards are developed to govern their use to help reduce the threat of pests while minimizing the impact to trade. This report summarizes current technologies and suggests ways forward.
Midply shear wall, which was originally developed by researchers at Forintek Canada Corp. (predecessor of FPInnovations) and the University of British Columbia, is a high-capacity shear wall system that is suitable for high wind and seismic loadings. Its superior seismic performance was demonstrated in a full-scale earthquake simulation test of a 6-storey wood-frame building in Japan. In collaboration with APA–The Engineered Wood Association and the American Wood Council (AWC), a new framing arrangement was designed in this study to increase the vertical load resistance of midply shear walls and make it easier to accommodate electrical and plumbing services. In this study, a total of 12 midply shear wall specimens in four wall configurations with different sheathing thicknesses and nail spacing were tested under reversed cyclic loading. Test results showed that the modified midply shear walls have approximately twice the lateral load capacity of a comparable standard shear wall. The drift capacity and energy dissipation capability are also greater than comparable standard shear wall. Seismic equivalency to standard shear walls in accordance with ASTM D7989 was also conducted. Results show that an overstrength factor of 2.5 and can be used to assign allowable design strengths of midply shear walls with 7/16” and nail spacing at 4” or 3” on center. For midply shear walls with 19/32” OSB, a higher overstrength factor must be used to meet the ductility criteria. The information from this study will support code implementation of the midply shear walls in Canadian and US timber design standards, thereby providing more design options for light wood frame structures in North America.
n the first year of this project, literature reviews were conducted to identify the code requirements on MT components and to survey the available LLRSs used in the MT structures. Conceptual MT midply wall systems meeting structural, fire, and acoustical performance requirements were proposed. An advisory group meeting was held to evaluate the practicability of the proposed MT midply systems. In the next fiscal year, the proposed MT Midply will be optimised further according to the comments and suggestions from the advisory group. Analytical evaluation of the proposed MT Midply wall systems along with necessary tests will be conducted. Based on the evaluation, a go / no-go decision will be made as to whether the study should be continued for the proposed MT Midply.
This study focuses on measuring the wood moisture content (MC), temperature, and relative humidity (RH) (and the corresponding vapour pressure gradients) through each wall assembly to assess its hygrothermal performance. Controlled moisture loads, in the form of vapour
(achieved by maintaining a relatively high indoor RH) and liquid water (achieved by periodically injecting water to the wetting pads installed on the wood panels) are employed to stress these walls for investigating their moisture-related behaviour. After the wall panels and most instruments were installed but with the CLT directly exposed to the interior environment, a high indoor RH in range of 70-80% was maintained, starting mid-December 2020 inside the test hut to condition the wood to achieve comparable moisture gradients among the eight CLT panels. The test walls were closed in with interior framing (and interior insulation of walls No. 1 and No. 2) and drywall installed, followed with interior finishing in late January 2021. The indoor RH was afterwards set to be around 50%. Water injection is planned to start in the summer of 2021. Test results and performance of these walls will be presented and discussed in future reports.
Design for Disassembly and Adaptability (DfD/A) is a sustainability approach that can help extend the lifespan of buildings, reduce generation of construction waste at the end-of-life and reduce construction’s footprint as well. This study qualitatively assesses six light wood-frame exterior wall assemblies designed for thermal performance. The assemblies studied are typical of low- and mid-rise wood buildings.
Results indicate that the exterior wall systems tested against the evaluation grid have a score of 15 points out of 40 points. Mere focus on thermal performance with no attention to deconstruction of components at the end-of-life is the reason for the poor score received from the evaluation. Findings indicate the need for incorporating DfD/A principles at the early-design stages of systems.
Building on the success of midply shear walls for wood-frame construction, a multi-year research project was initiated at FPInnovaitons to develop MT version of midply shear wall systems that have greater structural capacities, fire, and acoustical performance.
Le présent document a été élaboré en vue de faciliter la construction industrialisée d'enveloppes de bâtiments à base de bois (murs extérieurs, toits), et donc de répondre aux exigences accrues en matière d'efficacité énergétique.
Manufacturing equipment ranges from manual, semi-automated to fully automated. Software developers have developed suites of applications for structural design, computer aided
design/drafting (CAD), computer aided manufacturing (CAM), building information modeling (BIM), and communication protocols to link production machineries. To further improve production process and material handling, it is essential to rationalize the sectors, review the current status, and identify technology gaps.
Les usines de construction modulaire fabriquent des composantes structurales comme des fermes de toit ou des panneaux de mur ou de plancher qu’elles assemblent en modules soumis à une finition avant d’être expédiés à un chantier. Les usines de construction par panneaux produisent de grandes quantités de panneaux de mur ou de plancher qui sont assemblés sur place.
National Building Code of Canada (NBC) 2020 is the latest edition of the national model code that will be published towards the end of 2021. Based on the best available information from the Standing Committee on Earthquake Design (SCED) at the time of writing this report, the seismic design demand in the NBC 2020 has increased for all site classes for many locations across the country. Also, there are other changes in NBC 2020 that might impact the seismic analysis and design of timber buildings. The main objective of this report is to compare the NBC 2020 to the 2015 edition, with emphasis on the level of the seismic design loads (demands), and potential impacts on the analysis and design of timber buildings.