This guide is intended to discuss mold-related issues and to assist the industry in the delivery of clean, mold-free products to the marketplace. Mold continues to be undesirable on wood products and can cause rejection of shipments by the customers and economic losses to the industry. This report provides an historic perspective on mold, defines mold and discusses why it became a major issue in the marketplace and how this relates to wood products. The main factors required for mold growth and expansion are discussed, as are methods of limiting mold growth. The best method of mold control is moisture control, which includes initial drying and keeping wood products dry.
Specifically we give best practice guidelines for controlling mold on logs, lumber, plywood/veneers, other composite panel products, wood chips/residues, and for wood products in service (buildings). Lumber is one of the key products of the wood industry and several specific guidelines in regard to mold control for lumber are available and covered in depth. This includes air-drying, kiln-drying, phytosanitary heat treatment, and chemical prophylactic treatment of green lumber. Some circumstances where control of moisture is not feasible will require either chemical treatments or water barriers to prevent mold growth. There is also a special section on lumber packaging and wrapping, and water repellents. Finally, the report reviews existing guidelines for mold cleaning and remediation.
This guide explores how the building industry in British Columbia can meet the challenges of reducing energy use in buildings, in part by effectively accounting for the impact of thermal bridging.
Most practitioners will find PART1 and Appendices A and B to be most useful. PART 1 outlines how to effectively account for thermal bridging. Appendices A and B provide a catalog of common building envelope assemblies and interface details, and their associated thermal performance data.
Researchers and regulators will be interested in PART 2 and PART 3, and Appendices C to E. They contain the cost-benefit analysis, and discussion on significance and further insights, of using this guide to mitigate thermal bridging in buildings.
[Available to the public: http://www.bchydro.com/powersmart/business/programs/new-construction.html?WT.mc_id=rd_construction]
FPInnovations commissioned the Athena Institute to develop a biogenic carbon calculation tool for use
in Environmental Product Declarations, EPD’s, developed under their Product Category Rules, PCR, for
North American wood products. Athena has developed two such tools to supplement two types of LCA
Cradle-to-gate: Cradle-to-gate LCA refers to those that begin in the forest “cradle” and end with the
packaged product at the manufacturing “gate”. Business-to-business, B2B, EPD’s are developed form
Cradle-to-grave: Cradle-to-grave LCA includes the cradle-to-gate processes as well as the transportation
to user, end-use, and end-of-life treatment or “grave”. Business to Consumer, B2C, EPD’s are developed
from cradle-to-grave LCAs.
In the construction of buildings, the timber-concrete (TCC) system can be a cost-competitive solution for floors with longer spans, since the mechanical properties of the two materials are used efficiently. Furthermore, the additional mass from the concrete improves the acoustic performance compared to a timber floor system alone. Nevertheless, TCC floors are not commonly used in buildings in Canada, due to the absence of technical guidelines for such types of structural systems in this country.
“Conservatively, there are an estimated 10 million houses in North America with springy floors or other structural problems” http://www.ridgwaystructuralsystems.com. We have found that the springy floors were caused by improper design or construction practices. The improper design is specially true for engineered wood floors because of lack of proper design method and knowledge.
This report is focused on the development of a new design guide to demonstrate that floor vibration problems can be solved through proper design and construction practices. The design guide is aimed at assisting those who are involved in wood-framed floor design, construction, and product development, in better controlling feelable vibrations and in achieving optimum value engineered (OVE) floor systems.
The scope of this design guide is limited to: wood-framed floors, or light-weight floors with a fundamental natural frequency above 10 Hz; controlling feelable vibrations, but not “drum effect” vibrations induced by normal walking; ensuring human comfort.
The design guide first explains the fundamental physics behind the vibrations induced in wood-framed floors by normal walking and the human response to vibrations. The general theory of vibrations relevant to the vibrations induced in wood-framed floors by normal walking is included in Appendix I. Then a mechanics-based new design method and its verifications are presented. Working examples are provided along with the design tool, i.e. an ”Excel spread sheet” that incorporated the design method and the working examples to assist readers in using the new design method effectively. Various remedy techniques are provided along with a case analysis of unsatisfied floors. Finally, the design guide includes a systems analysis of the effects of various construction practices on floor multi-performance attributes, ease of installation and cost effectiveness. This assists the user in adopting a systems approach for designing an optimum value floor system when developing practices for controlling floor vibrations.
The knowledge, experience and understanding of floor vibration control compiled in this design guide is based on over ten years of research, with contributions from various floor researchers, practitioners, product manufacturers and home owners that Forintek has encountered in the course of conducting various floor studies.
This design guide is not the end of the process. Rather, it is considered to be part of an ongoing process to provide practitioners and researchers with state-of-the-art information to control floor vibration, as our knowledge of floor vibration and noise control, floor construction products and techniques evolve over time.
A new design Section on Lateral Load Resisting Systems (LLRSs) was introduced in the 2009 edition of Canadian Standard for engineering Design in Wood (CSA O86). The activities presented in this report (development of technical papers, development of technical polls and attending various code committees) have a goal to continue the work in this field by further improving the new Section on LLRSs by implementing additional design information for other wood-based structural systems and assemblies. During the last two years, several technical polls and papers were developed and presented to various code committees for future code implementation. These activities will help design engineers to use timber in structural systems in residential and non-residential buildings in Canada and the US.
A new design Section on Lateral Load Resisting Systems (LLRSs) was introduced in the 2009 edition of Canadian Standard for engineering Design in Wood (CSAO86). The activities presented in this report (development of technical papers, development of technical polls and attending various code committees) have a goal to continue the work in this field by further improving the new Section on LLRSs by implementing additional design information for other wood-based structural systems and assemblies. During the last two years several technical polls and papers were developed and presented to various code committees for future code implementation. These activities will help design engineers to use timber in structural systems in residential and non-residential buildings in Canada and the US.
Thin circular saws can suffer from a vibration phenomena called critical speed instability. At the critical speed, a resonant condition occurs where a saw can snake slowly from side-to-side producing unacceptably large sawing variation. To avoid this problem, most circular saws operate at 10 to 15 percent below the first critical speed. Unfortunately, this practice limits reductions in saw plate thickness and corresponding improvements in lumber recovery. Recently, several mills have been able to operate guided splined-arbor saws above critical speed. These supercritical speed saws offer significant sawing performance improvements by allowing both high recovery and high production rates. The use of these saws remains rare, however, and very little knowledge is available to guide mills that want to investigate this promising area. This report describes laboratory tests involving two supercritical speed saw configurations which are operating successfully in industry. Detailed descriptions of these configurations are given and guidelines for use are described. Idling and cutting tests were completed to characterize vibrational behaviour and demonstrate sawing performance levels. Tests were done to investigate the effect of changes in saw tensioning, saw tooth design parameters, saw and feed speeds and saw plate thicknesses. Test results confirm that for the sawing configurations tested, operating speeds can be found in the supercritical speed region where stable idling behaviour allows successful sawing. As with conventional saws, sawing accuracy is best at lower feed speeds. However, by operating at supercritical speeds, acceptable sawing accuracy can be achieved at higher feed speeds than are possible using conventional saws. Saw tensioning allows further increases in saw and feed speeds, but is not essential for supercritical speed operation. Changes in saw thickness strongly affect sawing performance levels and lumber recovery. Thinner saws have higher sawing variation and must operate at lower feed speeds than thicker saws. Curves showing the relationship between saw plate thickness, feed speeds and sawing accuracy are presented which can be used to assess the economic benefits of the supercritical speed saws that were tested. Supercritical speed circular saws offer considerable potential to improve sawing performance and increase lumber recovery. These saws allow reductions in saw kerf widths while maintaining high feed speeds and acceptable sawing accuracy.
Ce guide fournit les éléments principaux permettant d’atteindre une meilleure qualité de surface et de copeaux avec les équarrisseuses de type conique. Un guide de résolution de problèmes contient de l’information complémentaire selon les problèmes rencontrés. Des formules de calculs sont aussi expliquées.
Depuis quelques années, le revêtement en bois massif a retrouvé ses lettres de noblesse après avoir cédé des parts de marché aux revêtements synthétiques. Ce gain de popularité s’explique notamment par les nombreuses améliorations apportées par les manufacturiers à leur gamme de revêtements, et ce, tant pour ce qui est du moulurage de leurs profilés que de la durabilité de la teinture appliquée en guise de finition, en passant par un rehaussement significatif de la qualité de la fibre utilisée.