Western red cedar’s natural durability is attributed to a unique set of heartwood extractives. These can be lost in service due to leaching and biological activity. The microorganisms responsible for extractive depletion from wood in service are not well understood, and it is not known whether such loss of extractives has a substantial impact in reduced durability. The present work exposed western red cedar blocks in ground contact and above ground in a high humidity environment for one year. Trichoderma spp., Penicillium spp. and zygomycetes were found to initially colonise the blocks. This coincided with significant losses of extractives. Biological degradation is the most likely cause of extractive depletion in the ground contact and above-ground exposures in this experiment. This degradation corresponds to reduced decay resistance to at least one brown rot fungus.
Western red cedar’s natural durability is attributed to a unique set of heartwood extractives. These can be lost in service due to leaching and biological activity. The microorganisms responsible for extractive depletion from wood in service are not well understood, and it is not known whether such loss of extractives has a substantial impact in reduced durability. The present work exposed western red cedar blocks in ground contact and above ground in a high humidity environment for one year. Trichoderma spp., Penicillium spp. and zygomycetes were found to initially colonise the blocks. This coincided with significant losses of extractives. Biological degradation was the most likely cause of extractive depletion in the ground contact and above-ground exposures in this experiment. This degradation corresponded to reduced decay resistance to at least one brown rot fungus.
In a follow-up experiment designed to confirm extractives losses associated with above-ground exposure, 30 blocks were exposed above ground for six months and compared to matched, unexposed samples. Extractives analysis of these samples revealed significantly lower concentrations of the thujaplicins and thujic acid in exposed samples. Concentrations of plicatic acid and methyl thujate were not significantly different in exposed samples, while thujaplicatin methyl ether showed a slightly higher concentration in the exposed samples. These data confirm earlier observations on unmatched material.
Permission for the print copy of this book has been given to the BC Log and Timber Association. Any print copies of this book must be ordered through their website. FPInnovations only sells copies of the electronic version.
This is a very unique book that focuses exclusively on converting the log shell into a finished home. It is a must-have guide for builders, general contractors and do-it-yourself enthusiasts. It covers steps right from the foundations to ensure that the sill log will be tightly sealed, all the way to the installation of kitchen cabinets in a manner that will allow the logs to settle without damaging the cabinetry. Each chapter of this book shows one aspect of the finishing process and provides several options using a diverse selection of techniques and products available today. Three-dimensional color drawings depict the placement of sealants e.g., gaskets, wind-proofing membranes and vapour barriers, and explicitly show how to use and install them so that they effectively perform their function. The book is invaluable educational material and food-for-thought when developing new log building solutions and assemblies.
A series of studies were conducted in this project including 1) Evaluating the effect of the wetwood control agent on wood weight loss; 2) Evaluating the effect of the wetwood control agent on wood strength loss; 3) Evaluating the effectiveness of the wetwood control agent on western wood species; 4) Investigating natural distribution of the wetwood control agent in balsam fir logs and lumber; 5) Stimulating natural colonization and enhancing growth of the wetwood control agent; 6) Optimizing biological formulation and shelf life; 7) Studying the feasibility of biological stimulation for natural colonization; and 8) Identifying potential commercial partners, product registration and new substances notification.
The results showed that the two wetwood control isolates were able to cause weight losses of the fresh sapwood of balsam fir, sub-alpine fir and hemlock tested; however, the amount of the weight losses caused by the wetwood control agent was significantly lower than the one caused by the true decay fungi. The wetwood control isolates were unable to cause wood strength loss of treated balsam fir lumber after an outside summer storage of 8 weeks. Both isolates of the wetwood control agent grew well on the western wood species such as sub-alpine fir or hemlock and reduced moisture contents from these wood species.
A total of 456 cultures were isolated from bark of balsam fir logs, 295 cultures were isolated from the wood of logs, and 110 cultures were isolated from sawn lumber. Among these cultures, 2% of the wetwood control agent were isolated from bark, 6% of them were from wood and 5% from lumber. Studies also showed that pre-treating wood with 1% bleach solution or steaming at 100°C for 10 minutes could stimulate the growth of the wetwood control agent on balsam fir wood.
Considering the high efficacy and the low cost, the best formulation of the wetwood control agent was identified as a concentrated spore suspension. Such a formulation could be stored or transported at ambient temperature, at 4°C or at -20°C; however, the highest survival rate was observed from those cultures stored at 4°C, which survived 100% for 3 months and 68% for 6 months. The moisture content loss from balsam fir logs treated with the culture of the wetwood control agent was 43.6% after a 2-month storage period. The potential commercial partners for commercializing this bio-product have been identified.
Recent work at FPInnovations within the Transformative Technologies program has focused on developing information to assist the Canadian Wood Preservation industry to transition to carbon-based preservation systems. One of the aims of the research is to identify ways of processing wood treated with carbon-based preservatives at the end of its service life. There is also concern regarding biodegradation of carbon-based preservatives during the service life leading to premature failure. This review summarizes what is currently known about the biodegradation of carbon-based actives and identifies knowledge gaps to guide future work in this area.
Transformative Technologies - Federal Initiative 1
Vancouver, British Columbia
New carbon-based preservative formulations have been developed for above-ground applications as potential replacements for the current generation of copper-based preservatives for certain applications. It is important to study the organisms that can colonize wood in the presence of these preservatives, particularly those that may be able to degrade them. FPInnovations has decking material treated with carbon-based preservatives currently in test under contract to a range of clients and the opportunity was taken to sample and identify some of the organisms colonizing some of this material. Identification was done utilizing molecular methods, specifically PCR and DNA sequencing and a profile of early colonizers was developed. Preliminary results have picked up species that may be capable of degrading the preservatives, several soft-rot species plus two white-rot species, and several parasitic basidiomycetes that may indicate that decay is already underway.
Western redcedar (WRC) is well known for its natural durability. However, the extractives associated with this durability are not fully understood. The literature primarily credits the thujaplicins, with a lesser role for the lignans; however some previous work had identified highly durable material with low thujaplicin content. To further elucidate the roles of various extractives, the decay resistance of WRC stakes at four test sites was compared with extractives data to examine their association. Plicatic acid, a lignan, was strongly associated with the decay resistance of WRC wood in ground contact. An unidentified, unquantified compound (B) also appeared to be strongly associated with decay resistance. The thujaplicins were only weakly associated with the decay resistance of WRC wood in ground contact.
Lacking the UV protection provided by copper, carbon-based preservative-treated wood used in many above-ground applications will require coating to meet consumer demand for weather resistance. While earlier metal-based preservatives were true solutions, many of the formulations of carbon-based preservatives rely on surfactants for solubility or dispersion in water. These surfactants can potentially react badly with the dispersion agents in the existing coatings on the market. The present work investigates the performance of six selected coatings on white spruce heartwood and ponderosa pine sapwood untreated and treated with one of three carbon-based preservatives. An earlier report described coating performance after 500 hours of artificial weathering (Stirling and Morris, 2010). The present report describes coating performance after 1000 hours of artificial weathering. The general ratings of the coatings on spruce were typically one to two points higher than those on pine indicating that spruce was a more stable substrate. Contrary to the initial concern, treatment with carbon-based preservatives was associated with coating performance under accelerated UV exposure similar to, or slightly better than, that on untreated wood.
A major constraint to the Canadian wood preservation industry in both domestic and export markets is the difficulty of penetrating Canadian wood species with preservatives. FPInnovations has put considerable effort into various forms of improved mechanical incising but these have not been adopted by the industry due to adverse effects on throughput and appearance of the final product. Recently, work in Europe has shown promising results from biological incising using white-rot fungi that colonize wood relatively rapidly but decay slowly. The use of European isolates of fungi in North America may be constrained by phytosanitary concerns. This report covers an experiment to screen North American isolates of white-rot fungi for potential as biological control agents. A modification of the soil-block test method was used to evaluate the ability of a range of fungi to improve permeability without affecting strength properties. Wood samples were exposed to the fungi for zero, two, four and six week time increments and were then treated with a 1.5% ACQ-D solution. Preservative uptake was calculated based on change in weight before and after treatment. Two isolates of Dichomitus squalens were found that dramatically increased preservative uptake. These samples were tested for strength loss and preservative penetration. Spruce samples exposed to D. squalens isolate 78A for six weeks were completely penetrated with preservative (19 mm depth) in all six samples. D. squalens 78B also showed promising results in pine and spruce samples based on uptake and penetration data. No stiffness loss was detected in any of these samples based on results from the crushing tests.
There is increasing demand for natural looking wood in exterior applications. If wood finished with transparent and semi-transparent coatings is to compete with other building materials that claim to be low maintenance, the time between re-finishing has to be considerably extended. The use of low-nutrient wood materials, carbon-based preservative treatments, and protective pre-coats that reduce photo-degradation may be able to reduce the maintenance requirements for exterior wood products. The effectiveness of various combinations of protection systems were investigated in field tests set up in Maple Ridge, BC and Saucier, Mississippi. This report describes the initiation of these tests and results after six months of exposure.
In general spruce heartwood samples performed better than the pine sapwood samples. The semi-transparent film-forming finish (F1) performed better than the transparent film-former (F2), which performed much better than the semi-transparent penetrating stain (F3). In general, preservative-treated wood performed better as a substrate than untreated wood. The protective pre-coats were relatively effective under the transparent film-former. Further evaluations are needed to determine the efficacy of the protective pre-coats under the semi-transparent film-former.
La pression nominale au sol est un critère important utilisé pour prévoir les effets du poids et de la configuration d’une machine sur les sols forestiers durant les activités de récolte. Le présent rapport traite du concept de pression nominale au sol, de la façon dont il s’applique à différents types de machines ainsi que l’effet des diverses configurations des machines.
There is interest in the lumber and truss industry to supply and use fingerjoined lumber for metal plate connected wood trusses. To support this, it is necessary to provide evidence that fingerjoined lumber meeting the requirements of a recognized fingerjoined lumber product standard can be used with the lumber design provision provided in the governing wood engineering design code.
In consultation with the truss and lumber industry, it was agreed that fingerjoined machine graded lumber meeting the requirements of the National Lumber Grades Authority (NLGA) Special Product Standard 4 (SPS 4) would be assessed for truss applications. The assessment would need to show no issues with applying the lumber design provisions in Clause 5.5.13 of CSA O86, the Canadian Engineering Design in Wood Code, to NLGA SPS 4 fingerjoined lumber. This is necessary because Clause 5.5.13 was originally developed for non-fingerjoined lumber and applies specifically to the design of lumber in truss applications.
The tests carried out under this program included bending test specimens with 1 to 4 joints per specimen tested to failure under three different bending moment configurations, and single fingerjoints tested to failure under pure axial tension or compression, and then under eccentrically applied axial tension or compression to induce bending in addition to the axial loading. All test specimens were prepared using a 2100f-1.8E grade spruce-pine-fir lumber and because the test to failure was typically less than 5 minutes, polyvinyl acetate (PVA) adhesive was used to bond the fingerjoints to facilitate joint fabrication.
Additional testing was also carried out to extend the testing protocol developed in 2008-09 for assessing fingerjoint adhesives under sustained tension loads. Samples bonded with a known performing adhesive, phenol resorcinol formaldehyde (PRF), were substituted with samples bonded with PVA, a known poor performer under sustained loads.
In the bending test, test span configuration and characteristic number of joints showed strong effects on the average bending capacity of the fingerjoints. While more joints in the region of maximum bending moment were expected to contribute to lower bending capacities, this was not as evident in this study. This is likely due to the small sample sizes and the tight control over the joint strength (i.e. low strength variability). Instead, having one or more fingerjoints in the maximum moment zone but near the load points appeared to have a stronger effect. The bending strength reductions were on the order of 5 to 10%.
In the combined loading test, loading eccentricity showed a strong effect on the capacity of the fingerjoints in both tension-bending and compression-bending. The tension-bending interaction should be noted for those evaluating online or offline tension test results. Both the tension-bending and compression-bending results are consistent with the assumptions in the CSA O86 design code.
This project looks at the preferences for structural wood products within the top 20 residential homebuilding markets in the United States. A first objective was to document the attributes demanded by homebuilders in structural floors, walls and decking applications. The project further characterizes the performance of wood, steel, and concrete on these demanded attributes. The study was completed into two subsequent steps. The first step was a quantitative survey of an average of 50 builders per market in the Top 20 markets. The second step included focus groups with homebuilders in four of these markets: Philadelphia, Chicago, Phoenix, and Denver.
Results show that wood products continue to be under pressure from the growth of concrete in wall and floor systems. While the basis for growth in the use of concrete was traditionally found in the U.S. South, this survey points out that western and northern cities of the United States may become susceptible to the growth of concrete slab floors. The intended future use of concrete in walls was also high in some Northern jurisdictions such as New-York, Minneapolis, Washington, and Philadelphia, indicating a possible spread of concrete use in walls in some markets which traditionally relied on wood. However, the discussions with builders in Chicago and Philadelphia tempered this threat, as most of participants to the focus groups were much relying on wood for their projects. Nevertheless, the survey shows that, according to homebuilders, concrete significantly outperforms wood on durability, strength/structural integrity, and acoustic performance. Two of these attributes (durability and strength/structural integrity) are among the Top 3 important attributes in both floor and wall applications. With that said, it is important to point out that wood obtains a high score on the performance scale for both these attributes, despite the difference with concrete. These attributes may guide the development of future wood based products and building systems. On code acceptance, wood also scores high on the performance scale, and is at least equal with concrete.
Wood based sheathing (OSB, Plywood and Fiberboard) detain over 85% of the market in 17 of the 20 metro areas. However, foam and kraftboard sheathing have gained some importance in selected markets. In Chicago, the market share of foam and kraftboard together even reaches 24%. When comparing the performance of wood-based sheathing with foam-based sheathing, plywood and OSB are significantly thought superior to foam for strength, structural integrity, resistance to jobsite damage, environmental friendliness, and code acceptance. Foam is said to perform better than OSB or Plywood for both acoustics and energy performance. As a result, acoustics and energy performance in sheathing applications prove to be valuable paths for product development. This was confirmed in focus groups sessions.
Most generally, builders interviewed for the discussion sessions expressed the need for new products addressing their concerns. In focus group sessions, labour issues came out as one of these concerns (except in Chicago). Especially, the current housing downturn has forced many trades out of the homebuilding sector, and most builders met fear that there will be a severe shortage of qualified labour once the housing market rebounds. Other issues that builders actively pursue include a combination of insulation and structural properties for sheathing (confirmed by the quantitative research), low maintenance and low call-back products, and ease of installation. From the discussion sessions, there is also room for new insulation products.
Composite decking has captured at least 20% market share in 12 of 20 of the metro areas. The highest market shares are found in Denver (71%), Washington (50%), Seattle (45%), and Philadelphia (40%). Clearly, composite decking now offers the greatest competition to wood in decks. This is shown by the satisfaction measures of decking materials which are greater for tropical hardwood and composite/plastic lumber than for wood, treated or not. Composite materials seemingly suit better the most demanded attributes, including durability, appearance, and longevity. The importance of low maintenance was further confirmed through the focus groups.
The current Canadian Lumber Properties program was established to support multi-year research on topics judged by the industry to be critical to the safe and viable use of Canadian dimension lumber in structural applications. This program, in combination with the National Lumber Grades Authority’s grading rules and the accredited third party grading agencies form the backbone of the Canadian lumber quality system. This system enables Canadian lumber producers to grade and ship Canadian lumber for use in North American and overseas structural building applications.
When initiated in 2005, the program focussed on five areas. The effort is now focussed on three areas: 1) maintenance of existing lumber design values by means of an ongoing lumber properties monitoring program; 2) working with the US/Canada task group established to guide the development of standard procedures published in ASTM D1990 and used in the establishment of lumber design values; and 3) liaise with university-based research groups to leverage research suitable for addressing longer-term research needs in the area of lumber properties.
One of the planned activities for 2009-10 was the start-up of a trial on-going lumber properties monitoring program. The program, which is a longitudinal survey of lumber produced from mills across Canada, would have been modelled after the Pilot Ongoing Monitoring program that began in 2006 and ended in 2008. Because of the severe downturn in the industry starting in 2008, the proposed 2009-10 program needed to be postponed to accommodate the shortfall in industry funding. There were also concerns with the significant changes in production levels both within and between regions, and the potential disruptions to sampling because of unanticipated mill closures. Available resources were instead directed at establishing how best to respond to practical issues observed during the downturn, such as the closure of a mill that would have or had been providing samples. Following discussions during the year and consideration of possible alternatives, it is recommended that the sampling plan as used in the Pilot program be restarted. Additional details on the augmented mill list to account for mill closures are provided in the recommendations section of this report.
In the other major area of study, University of BC (UBC) and US Forest Products Laboratory (USFPL) statisticians met to discuss and evaluate alternatives to the ASTM D1990 procedures for developing design values for groups of wood species. Although the proposed alternative procedures would address one or more of the statistical anomalies identified in the ASTM D1990 procedure, the American Lumber Standard Committee (ALSC) Lumber Properties Task Group (LPTG) charged with reviewing the potential changes did not see any practical improvements to warrant changes to the procedures but suggested that the effort focus on establishing criteria for species grouping. Because of the potential inter-relationship between the species grouping procedures and other procedures used to assess in-grade lumber properties, it is recommended that efforts be maintained in this area and adjusted as required to respond to the needs of the LPTG.
Lastly, in late 2009, the UBC Dept. of Statistics and the Simon Fraser University Dept. of Statistics and Actuarial Science were awarded a research grant by the Natural Sciences and Engineering Research Council (NSERC) of Canada to establish the “Forest Products Stochastic Modeling Group”. FPInnovations is the industrial collaborator on this initiative. Several student projects targeting longer-term lumber properties research needs have been initiated, and a sample of suggested projects is included in the appendix of this report.
Programme des technologies transformatrices ; Projet no 201000339
La tendance vers la construction verte est en croissance fulgurante depuis les dix dernières années. On estime que le marché de la construction verte représente environ 5 % du marché actuel de la construction. La majorité des bâtiments conçus ou construits dans une perspective environnementale se situent dans les secteurs non-résidentiel ou multifamilial. C’est dans ce contexte que nous nous sommes intéressés à la possibilité de développer et vendre des isolants faits à partir de bois; un matériau généralement reconnu pour ses vertus écologiques. La principale application ciblée dans le rapport est les cavités murales.
Ce rapport se présente en cinq (5) principales sections :
Le marché mondial pour les produits isolants est énorme. Il est estimé à plus de 190 milliards de pi² base R-1. Près de 70 % de ce total est destiné au marché de la construction qui comprend la construction résidentielle (45 %) et non-résidentielle (23 %). La majorité des isolants consommés à l’échelle mondiale sont utilisés en Amérique du Nord et en Europe de l’Ouest. De manière générale, le marché est dominé par les mousses plastiques et la fibre de verre. Le marché pour les isolants autres (alternatifs) oscille entre 2 et 6 % en fonction des marchés dont il est question. Cette proportion est généralement plus élevée dans la réparation et la rénovation que dans la nouvelle construction. Il existe des variations régionales qui sont documentées dans le présent rapport.
Structure industrielle :
Les isolants sont des produits dont la valeur unitaire est relativement faible. Il est par conséquent difficile de livrer ces produits sur de grandes distances. La majorité de la production mondiale se fait dans les deux grands marchés mondiaux soit l’Amérique du Nord et l’Europe de l’Ouest. Le tiers du marché (33 %) est dominé par cinq grandes entreprises qui opèrent plusieurs divisions. Elles sont : St-Gobain, Rockwool, Owens Corning, Johns Manville et Knauf. Il faut dire que les produits dominant actuellement le marché nécessitent d’importants investissements en capitaux. Ceci explique, en partie, cette concentration du marché au chapitre de la production.
Politiques et réglementations :
Cette section documente les grandes tendances qui risquent d’affecter la demande pour les produits isolants. L’augmentation des coûts de production des mousses pourrait offrir des opportunités pour d’autres produits. Les exigences relatives aux émissions de gaz à effet de serre pourraient jouer en faveur des isolants faits à partir de bois. Les politiques de réutilisation des matières résiduelles présentent des opportunités quant à l’utilisation de ces résidus pour fabriquer des isolants. La hausse des exigences de performance énergétique exigera l’amélioration des produits communément utilisés ainsi que des innovations à partir des matériaux moins fréquemment employés.
Performance environnementale :
Cette section montre que les produits isolants à base de bois peuvent contribuer à l’obtention de 8 à 9 % des points pour les systèmes de certification LEED et Green Globes. Il faut toutefois être conscient que l’isolant représente une petite proportion des matériaux entrants dans la construction d’un immeuble (<1 % en valeur). Ceci démontre l’intérêt, du point de vue de la construction verte, à développer des produits qui ont d’autres fonctions que simplement celle d’isoler.
Comportements et exigences d’achat :
Des entrevues exploratoires auprès d’architectes et autres utilisateurs d’isolant ont démontré un intérêt pour des produits plus verts. Les principaux facteurs intervenant dans la sélection du matériau isolant sont sa résistance thermique, son coût et la familiarité avec le produit. Les produits isolants conventionnels ne reçoivent que très peu d’intérêt de la part des architectes. L’isolant n’est pas perçu comme étant très innovateur (c’est plus ou moins une commodité) et a peu d’incidence sur le concept (esthétique ou fonctions) du bâtiment. Une des tendances qui semble poindre actuellement à l’horizon est celle des isolants qu’il est possible d’agrafer par l’extérieur du bâtiment.
Les autres sections du document présentent le contexte dans lequel le projet s’est exécuté (contexte, objectifs, équipe de projet, etc.) et font état des conclusions à retenir (discussion et conclusions). Les propriétés et caractéristiques générales des différents matériaux isolants sont présentées en annexe. Cette section complémentaire recense des exemples de produits pour chacun des principaux types de matériaux utilisés sur le marché incluant la fibre et la laine de bois.
Les informations colligées dans le cadre de ce projet permettent d’établir ces constats généraux :
À court et moyen terme, les principaux marchés pour l’isolant fait à partir de bois sont le marché non-résidentiel et multifamilial.
Le positionnement du produit isolant bois devrait être du côté des produits verts ou respectueux de l’environnement. Il ne s’agit pas d’un matériau dont la performance surpasse les matériaux communément utilisés.
Pour profiter pleinement de ce positionnement stratégique, le(s) produit(s) développé(s) devrai(en)t :
o Incorporer d’autres fonctions (pare-air, pare-vapeur, pare-feu, revêtement structural extérieur, parement extérieur, structure, etc.).
o Utiliser des matériaux issus de la démolition d’immeubles existants, fibres agricoles et autres intrants avec une faible empreinte écologique.
o Être analysés objectivement par l’entremise d’une analyse de cycle de vie.
La conclusion du rapport soulève certaines avenues de recherche pour les années à venir. Parmi celles-ci, on note les pistes suivantes :
Meilleure connaissance des types de construction les plus susceptibles d’utiliser des isolants verts faits à partir de bois.
Critères (incluant le prix et spécification de produit) recherchés par les différents utilisateurs.
Identification des marchés industriels (pas liés à la construction) susceptibles d’être réceptifs à des produits à base de bois.
Potentiel d’utilisation des matériaux de différentes sources (récupération, agricole, etc.) dans la fabrication de produits isolants.
Développement des propriétés (ex. : résistance à la compression) et des procédés.
In 2008, FPInnovations, Feric produced “A Tree Planter’s Guide to Reducing Musculoskeletal Disorders" (MSDs). The guide was aimed mostly at planters in western Canada using the shovel as the planting tool but it had no provincial boundaries and it was equally applicable to similar operations across Canada. However, because eastern Canadian tree planters also use different tools, an eastern Canadian version of the Guide was produced to include those tools.