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.
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 this study market opportunities for treated glue-laminated (glulam) products were investigated in the industrial wood sector. The main benefits of treated glulam are through-product treatment and the ability to manufacture treated products in shapes and sizes that do not fit into common treating chambers. These attributes provide for very durable and large glulam structures that are appropriate for outdoor use. For these reasons bridges, power poles, and sound abatement barriers were investigated. These are markets where wood has lost market share to or is being challenged by concrete and steel substitutes.
The vehicular bridge market was once heavy to the use of wood. Today wood accounts for only 7% of the number bridges in the US and less than 0.9% of the actual surface area of bridges in place. In interviewing municipalities in Canada it is clear that wood is not the preferred material with many wood bridges being replaced by concrete. Further, none of the municipalities contacted were planning wood bridges. However, wood bridges are still being installed. In the US 0.9% of the bridges installed by area in 2007 were wood. This is good news as wood is holding its market share. Steering clear of high volume or large bridges, local bridges are well suited for wood as they are plentiful, small in scale, and many are in disrepair. If 20% of local bridges were built with wood in Canada this would have equalled approximately $51 million in wood bridge construction in 2007.
Municipalities are much more open to the use of wood for pedestrian bridges and overpasses. Their quick construction and aesthetics are positive attributes in this application. One municipality contacted is planning multiple wood pedestrian bridges in the next five years. However, for the purpose of this market review there is little published information on pedestrian bridges.
Noise abatement barriers are a good high-volume technical fit for treated glulam. Increases in traffic and current road infrastructure improvements will lead to more demand for sound abatement in the future. This market is dominated by concrete, but at a very high price. If treated glulam can give adequate durability and sound performance properties it would be approximately 20% cheaper than concrete. The market for sound barriers in Canada could utilize up to 10 mmbf of wood per year to construct 80 km of barrier. This product can also be marketed as a high-performance acoustic fence for residential markets.
Treated glulam was also considered for utility poles. It is transmission grade poles where glulam would best fit the market as the demand is for longer poles which are more difficult to get in solid wood. This type of pole is where wood is currently being displaced by tubular steel. If glulam poles were used in 25% of the replacement transmission poles per year this could equal 8 mmbf. Light poles or standards are another market to consider. While this is a relatively low volume market glulam light standards are a premium product in European markets.
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.
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.
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.
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. After 500 hours of artificial weathering there were few differences in coating performance between untreated and treated samples. Further weathering should be completed to potentially detect more subtle effects that these preservatives may have on coating performance.
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.