Ce rapport décrit les résultats d’études en cours ou antérieures réalisées par Forintek sur les méthodes utilisées pour l’aboutage du bois et la qualité des produits. Il donne une description détaillée des différents paramètres susceptibles d’affecter le procédé d’aboutage et la qualité du produit fini. Il contient également une masse de renseignements publiés dans le cadre d’ateliers, de conférences ou de revues techniques. Cette information a été regroupée et intégrée dans un format simplifié de façon à être utilisable dans la fabrication des bois aboutés. L’un des chapitres porte sur le processus de qualification et de contrôle de la qualité des bois de charpente aboutés et décrit les normes canadiennes de produits spéciaux applicables. On trouvera à la fin de chaque section un paragraphe traitant d’idées de recherche novatrices, de questions importantes pour l’industrie canadienne du bois abouté et de lacunes dans les connaissances.
In this study builders and professional repair and remodellers were given a chance to evaluate 12 of the most common home siding products available in the market today. The products were evaluated on seven different attributes: price, maintenance, installation, attractiveness, status/image, fire resistance, and durability. Overall, fire resistance, attractiveness, and maintenance were selected as the most important product attributes by single-family homebuilders and repair & remodellers. The majority of respondents stated that their customers had a strong influence on their final choice of siding materials. In addition respondents were asked for their opinion regarding product popularity, rate of installation, substitution trends, and their choice of siding products for different categories of homes.
The market for hardwood component production is currently affected by low-cost components importation from Asia. Industrial automation is an actual option for the secondary manufacturing industry to counter this situation. Integrating a defect detection system is a complex process and selecting the right system is even more complicated. This study proposes an approach for assessing the defect detection capabilities of different systems as well as a decision support tool to guide the producer toward the adequate equipment. The study is limited to assessing defect detection capacities; the overall system performance, the optimization software and the cutting equipment are not analyzed.
Understanding the origin and characteristics of defects to be detected and the capacities and theoretical limits of vision technology are prerequisites. A sampling with defects that, due to properties such as their small size, are hard to detect, is assessed by each system and the results are compared. To date, the assessed systems are not capable of detecting all defects pertaining to hardwood component production. A decision support tool will make it possible to methodically select the equipment most appropriate to the producer’s needs and leads to an enlightened decision in terms of the producer’s priorities and expectations.
This report summarises progress in the second year of this project. Significant progress has been made towards achieving the original objectives of the project. In addition, several other applications of fire models have been identified that would further the interests of the Canadian wood industry and so appropriate research was initiated.
An objective of this project was to identify wood-stud walls that qualify as being of fireproof construction in Japan. To be classified as fireproof construction, a wood-stud wall must pass the 1 + 3 test in which it is subjected to a one hour fire-resistance test and then must support its load for another 3 hours as the furnace cools. Attempts were made to revise WALL2D to model the response of walls during the heating and cooling phases of an arbitrary fire. The revised model was to be used to model the response of walls in the 1 + 3 test and in furnished house fire tests run in Kemano. However, it turned out to be a major revision to include a cooling phase in WALL2D, but revisions were made to model a heating phase of an arbitrary fire. This was sufficient to get good agreement with temperatures measured within walls in Kemano. Revision of WALL2D to model the 1 + 3 test has been deferred until 2004-2005.
The Japan 2 x 4 Home Builders Association and the Council of Forest Industries have identified, by testing, wood-stud walls and wood-joist floors that pass the 1 + 3 test. These assemblies have been granted Ministerial Approval as being of fireproof construction. It is therefore possible to build 4-storey wood-frame apartment buildings in high-density urban areas. Employing models to identify assemblies that pass the 1 + 3 test is now less urgent, but will continue as models may suggest ways to optimise assemblies meeting the 1 + 3 test.
Another objective of this project was to undertake performance-based design of a building as a showcase study. Carleton University is developing a model to evaluate fire safety designs for 4-storey wood-frame commercial buildings. The first building to be analysed is a wood-frame version of the Carleton Technology Training Centre. The Carleton University model does not yet model the response of the structure of the building. To supplement Carleton University’s efforts, Forintek will undertake performance-based design for fire resistance of a wood-frame version of this building in 2004-2005.
While the initial completion date for this project was to be March 2004, it was intended that if other applications of fire models were identified that would further the goals of the Canadian wood industry, the project would be extended. During 2003-2004, several new applications of fire models were initiated:
A fire resistance model developed jointly by Forintek the National Research Council Canada is being employed to estimate the impact on fire-resistance ratings of the load applied to wood-stud walls during a test. This information would be useful when quoting the fire-resistance ratings of Canadian assemblies in export markets where lower loads are applied during fire tests.
A collaborative venture has been initiated with Australian researchers to model fires in large compartments (found in non-residential buildings) and the resultant response of wood-frame walls.
Data generated in fire tests conducted in furnished houses in Kemano is being used to assess the ability of current fire models to predict fire development in these houses and to predict the performance of a variety of building assemblies. If the models do a good job, one would have increased confidence in applying fire models in a performance-based design environment.
To demonstrate the good fire performance of wood-frame assemblies, three fire tests were run for visiting Chinese fire experts. Fire models were used to design the experiments to ensure that wood-frame assemblies were selected that could withstand the fire exposures envisioned in the tests.
As this is a relatively new field much of the emphasis of this study was on a literature review to help develop a theoretical platform to work from. It was found that the colour of wood appears in the literature in two ways. It appears qualitatively in marketing and value-added research, and it appears quantitatively in colour matching and quality control research. The present research study is the first known occurrence of the quantitative comparison of measured colour with measured consumer preference.
There has been considerable research into character marks in wood. This research has largely been based around traditional hardwoods as the result of increasing scarcity of high grades of lumber. However, more fundamental characteristics such a grain profile, rings per inch, and the presence of visual features such as rays and vessels have not been considered with respect to visual preferences.
Consumer preference data used for this study originated from the study “Consumer visual evaluation of underutilized Canadian wood species” (Fell, 2002). This was chosen as it has a great variety of species to analyze. However, in the survey consumers evaluated the species for overall appearance and not for specific end-uses. Therefore results of the current study are general to wood used in the home and do not apply to specific end-uses.
The consolidation of the homebuilding industry is meant to continue and to have profound impacts on the forest products industry. It is changing the way houses are built as well as the relationships between building materials suppliers and home builders. Along the consolidation way, builders are also gaining more purchasing power as evidenced by the lumber consumption of the Top 100 builders, estimated to near 7 billion Board Feet.
More than ever before, large homebuilders are considering direct and longer term agreement with suppliers of lumber and OSB. It is expected that, due to the emergence of longer term and more direct purchasing agreement, collaborative practices become more developed. As far as building techniques go, we assume that the componentization of the housing industry will keep its advance, especially in the large builder segment. Componentization not only brings more off-site fabrication, but it also relies on a higher engineering content in the housing construction process.
Currently, purchasing agreements are short term based either for lumber, structural panels, engineered wood products, roof trusses and prefabricated walls. However, when questioned about the future of their purchasing agreements, respondents clearly showed a propensity to develop long term agreement. Indeed, every participant to this study pointed out to longer term agreements with suppliers and, in some cases, raised the possibility of more exclusive arrangements. This observation was further confirmed in site visits.
While centralization of the purchasing process is not the preferred choice of every large builder, we hypothesize that the specifiers will increasingly be centralized in the future in the wake of national purchasing agreements. Meanwhile, it is clear that regional offices will continue to have their word to say. Materials selection is not a one way process from top to bottom, but the head office is likely to be involved even when the process is regional.
As of now, most of the interactions between large builders and their suppliers may be summarized as information exchange. This indicates a fairly low level of inter-firm co-operation. However, the majority of participants expect either a shorter supply chain, more direct relationships or more partnering over the next five years. In turn, information and communication technologies, either for fund transfer of business planning, will spread out.
Ce projet de recherche sur l’automatisation des procédés dans l’industrie des maisons préfabriquées, plus précisément la fabrication de murs fermés prêts pour l’installation sur le chantier, permet de documenter et de planifier une amélioration de productivité dans les usines déjà existantes ou encore à déterminer quel type d’usine il faudra établir en fonction du potentiel annuel de ventes de maisons préfabriquées.
Les résultats de ce projet sont présentés dans ce rapport. Des scénarios sont élaborés suivant divers degrés d’automatisation manufacturière. Les résultats démontrent que, suivant le marché de l’industrie de la maison préfabriquée, diverses options sont à la portée des manufacturiers.
Ce rapport intéressera les manufacturiers existants de même que ceux en devenir; car il donne un aperçu d’automatisation pouvant être apporté dans une usine de préfabrication.
This benchmarking study aims at providing the Canadian industry, agencies and governments with the necessary understanding of the knowledge and perception of wood roof trusses among specifiers in selected urban regions in China for ongoing and future promotions of wood roof trusses in China.
The objectives of this project are the following:
1. Assess current awareness, knowledge and perception of wood roof trusses in multi-family housing among specifiers (architects, engineers and builders/developers);
2. Examine how decisions on roofing/building systems and materials are made;
3. Determine best ways to transfer knowledge about wood roof truss systems to specifiers.
Two separate surveys were carried out for benchmarking wood use in roofs in China. The first survey was part of a survey of Chinese building specifiers (Benchmarking Chinese Building Specifiers (Cohen and Ding 2004)) carried out in October/November 2003. A second survey was administered during the Conference on Hybrid Building Construction in China and Wood Roof Truss Workshops in Shanghai and Beijing in December 2003.
Through the coordinated initiatives of industry and the Provincial and Federal governments, Canada has made significant progress in the acceptance of Canadian wood products and wood-frame construction in the codes and standards of China, Taiwan and South Korea. Technical input to support favourable revisions to the codes and standards in these countries has been spearheaded by Forintek staff, with support from representatives from various national organizations in Canada and the US. In this process, Forintek also has established a network of experts in these countries, which Canada can use in addressing potential future technical barriers.
The effort has resulted in changes to the Chinese quality inspection code (GB 50206) and the timber design code (GB 50005). The GB 50206 was released in July 2002. The inclusion of North American wood frame construction and products has helped speed up inspection for wood frame construction in China.
The GB 50005 was released in January 2004. The newly enacted code allows local engineers to design North American platform frame construction and specify North American species groups of structural lumber that are graded to rules that are compatible with those in Canada. Fire protection regulations have also been revised to position wood frame construction on the same playing field as buildings made of concrete and steel: for example, wood frame construction can now be built up to three storeys, and spatial separations can be as close as 4 m.
Progress has also been made in Taiwan. The revised Taiwanese timber design code approved in 2003 contains engineering and pre-engineered designs adopted from North America standards. The submission of technical comparisons of the Canadian and Taiwanese standards to the Taiwanese government will help the Canadian forest industries to obtain Taiwanese regulatory recognition that Canadian wood products in compliance with Canadian standards will meet the pertinent Taiwanese standards. This recognition will give Canadian suppliers a head start in establishing a share of the Taiwanese market.
The effort in 2003-04 builds on the successful working relationship established with the various codes and standards committees in China and Taiwan to assist them in introducing the North American wood frame construction system. Although it is understood that there are still a number of technical and market support items to address, this program ensures that a coherent infrastructure is developed to support the use of Canadian wood products in the Far East markets.
Building construction - Specifications - China
Building construction - Specifications - Taiwan
Building construction - Specifications - South Korea
Structural engineering - Specifications - China
Structural engineering - Specifications - Taiwan
Structural engineering - Specifications - South Korea
Des visites industrielles auprès des producteurs et des utilisateurs de panneaux collés sur chant ont été effectuées afin de définir ce qu’est un collage sur chant de qualité pour les produits d’apparence. Cette enquête répondait ainsi au premier objectif spécifique du projet. Lors des visites, des panneaux collés avec joints de bonne et de mauvaise qualité ont été recueillis pour examen au laboratoire de Forintek. Des mesures effectuées au microscope ont permis d’établir à 0.05 mm la valeur maximale acceptable de largeur du joint de colle d’un panneau. Les principales causes de joints problématiques propres à l’opération de délignage des bandes sont l’éclatement des fibres du bois sur l’arête, la trop grande rugosité de la surface sur chant et la mauvaise rectitude du trait de scie. La proportion de panneaux rejetés reliés à ces causes varie de 0.5 à 3 %. Les fentes en bouts et les joints ouverts aux extrémités dus à un retrait en largeur des bandes de bois suite à un séchage sont responsables d’une plus grande proportion de rejets de panneaux.
La plupart des usines visitées utilisent une scie à refendre à lame unique pour le délignage de bandes de largeur variable. Les modèles de déligneuse Mattison 202 et 404 sont utilisés dans la majorité des cas. Toutefois, certaines usines utilisent des modèles à scies multiples. Suite au délignage, la qualité du trait de scie est vérifiée de façon visuelle seulement. La présence de la pointe de diamant sur chant est utilisée comme indice de qualité collage. La seconde année du projet portera sur l’identification et le développement de méthodes d’évaluation des paramètres affectant la qualité collage.