Sustainability is playing a larger role in how we construct buildings. Many organizations are trying to reduce the life-cycle costs of their buildings by using “green building” practices. Currently, the US Green Building Council's Leadership in Energy and Environmental Design (LEED) program dominates the building certification scheme. Most new construction projects require a substantial amount of wood. The only approved wood source that can help qualify new construction for LEED certification is Forest Stewardship Council (FSC)–certified wood. Given the dramatic increase in new green construction, this study assessed the availability and use of FSC wood in LEED certification projects throughout New York State (NYS). We surveyed architects working on LEED projects to determine how FSC-certified wood was used and if they were having difficulty acquiring such wood. We suspected a green supply chain bottleneck at the sawmill level may impact end users in the LEED certification process. Our results indicate that architects are very knowledgeable about FSC wood and would like to incorporate it into their designs. We found no issues in sourcing FSC wood for LEED projects. Although architects prefer to buy locally, many must procure FSC wood outside of NYS. Many architects are paying a premium price for FSC wood, which may impact their decision to use it on future LEED construction projects.

Eight North American resin suppliers, representing 100 percent of the polymeric diphenylmethane diisocyanate (pMDI) market and >95 percent of the urea-formaldehyde (UF) market for interior wood composite panels (IWCPs), participated in an exploratory phone survey conducted in July and August 2008 that was designed to better understand their product positioning and “green” resin strategies. These eight firms were identified as the largest suppliers to the IWCP industry, which includes particleboard, medium density fiberboard, hardwood plywood, and hardboard. In 2007, the IWCP resin industry was highly concentrated and dominated by UF resins. Resin suppliers rated research and development work and technical support as the most important competitive advantage factors they used. Moreover, resin suppliers perceived the following product and service attributes to have the greatest importance to their IWCP customers: low formaldehyde emissions from finished panels (4.8 of 5), fast resolution of customer complaints (4.5), reduced volatile organic carbon emissions during panel pressing (4.3), support during resin trials (4.3), and on-time delivery (4.2). The regulatory environment (i.e., California Air Resources Board [CARB]) was the most important driver of IWCP resin manufacturers' green resin programs. Results showed a trend of increasing importance for green IWCP resin market development for the time periods defined as today, next 2 years, next 5 years, and next 10 years for pMDI suppliers, whereas UF suppliers rated green IWCP resin market development highly important over all four time periods.

Fuel ethanol, especially cellulosic ethanol, is likely to play an important role in renewable fuel development. This article reviews the main factors that currently drive fuel ethanol demand in the United States. In the short term, the phaseout of methyl tertiary butyl ether (MTBE) is important. In the long run, federal and state price support policies will play a dominant role in fuel ethanol demand. Both major demand factors and the current status of cellulosic ethanol manufacture are discussed. The current state of technology and the high capital cost for cellulosic ethanol production when compared with corn-based ethanol are major barriers to expanding the markets.

This article describes trends in board foot Scribner volume per cubic foot of timber for logs processed by sawmills in the western United States. Board foot to cubic foot (BF/CF) ratios for the period from 2000 through 2006 ranged from 3.70 in Montana to 5.71 in the Four Corners Region (Arizona, Colorado, New Mexico, and Utah). Sawmills in the Four Corners Region, Alaska, and California had the highest ratios, with each state's BF/CF ratio greater than 5.0. Among the states using the Eastside Scribner scale, the Four Corners Region had the highest BF/CF ratio (5.71), followed by California (5.03). Among states using primarily the Westside Scribner scale, Alaska had the highest ratio (5.29). All states or regions, with the exception of Alaska, have shown declines in BF/CF ratios over the last three decades. Montana has had the largest estimated decline (29%), followed by Oregon (23%). The increase in Alaska was the smallest change among states (<2%). Two major factors in the western United States appear to have largely influenced BF/CF ratios: changes in log diameter processed by western sawmills and the use of Westside versus Eastside variants of the Scribner Log Rule.

This article describes trends in three measures of lumber recovery for sawmills in the western United States: lumber overrun (LO), lumber recovery factor (LRF), and cubic lumber recovery (CLR). All states and regions showed increased LO during the last three decades. Oregon and Montana had the highest LO at 107 and 100 percent, respectively. Alaska had the lowest LO at 31 percent, followed by the Four Corners Region (i.e., Arizona, Colorado, New Mexico, and Utah). Because sawmills in the western United States use the Scribner Log Rule (SLR) as the unit of log input, higher LO is not a clear indication that mills are using improved sawing technology and techniques. At best, LO is an imprecise measure of production efficiency.

Better measures of lumber output per unit input include LRF and CLR. These measures are substantially better than LO because they are based on the cubic volume of solid wood fiber in a log, thus eliminating a number of the problems associated with the SLR. Oregon, followed by Washington, had the highest LRF (8.67 and 8.43 board feet lumber tally per cubic foot of logs, respectively) and the highest CLR (52% and 50%, respectively). Alaska had the lowest LRF and CLR. Changes in LRF and CLR suggest that sawmills in the western United States have used improved sawing technology and techniques to increase the volume of lumber recovered even as log sizes have decreased.

An experimental study was conducted to evaluate the length effect on the parallel-to-grain tensile strength of Chinese fir (Cunninghamia lanceolata) lumber. In all, 473 pieces of mechanically graded lumber were tested at gauge lengths of 150, 200, 250, and 300 cm. The lumber was sorted into matched groups according to the dynamic Young's modulus as measured using the longitudinal vibration method. The averages of the dynamic Young's modulus of high-grade (H) and low-grade (L) specimens were 11.8 and 8.9 GPa, respectively. Using nonparametric estimates, the estimated length effect parameters of H and L were 0.188 and 0.226, respectively, for the 50th percentile and 0.185 and 0.318, respectively, for the 5th percentile. It was then concluded that the different length effect factors between H and L could be used when using the lumber for practical purposes. The effect of increasing length on the tensile strength was a little larger in H but smaller in L for the 50th percentile compared with the 5th percentile. When two-parameter Weibull distribution functions were fitted to the strength data, the estimated shape parameters of the Weibull distribution by the parametric method were almost identical to the inverse of nonparametric parameters. The influence of defects such as knots on the lower tail of the strength distribution in H may be different than that in L.

Goals of this preliminary study are to better understand (1) earthquake performance of wood-frame shear walls carrying gravity loads, compared with walls without gravity load, and (2) performance of walls subjected to a sequence of earthquake motions, compared with walls subjected to a single earthquake.

Tests with simulated earthquake ground motions were conducted on 2,440 by 2,440-mm (8 by 8-ft) walls with 38 by 89-mm (nominal 2 by 4) Douglas-fir studs at 610 mm (24 in.) on center. Two oriented strand board (OSB) panels were installed and fastened vertically to the frame, and two gypsum wallboard panels were installed opposite the OSB. Partially anchored (PA) walls had two anchor bolts on the sill plate. In addition to the anchor bolts, fully anchored (FA) walls included hold-downs installed at the end studs. Ground motions were scaled to the 10 percent in 50 years probability of exceedance design level for Seattle, Washington, the traditional level associated with life safety performance.

For PA walls with dead load, failure modes were consistent with tests without dead load; however, additional fastener damage, common to FA walls, resulted from the additional resistance to overturning. PA walls realized a greater improvement in performance from dead load application compared with FA walls; performance appears to approach that of FA walls when dead load is applied. FA and PA walls subjected to a sequence of earthquake motions showed wall performance about the same as that of walls subjected to a single scaled earthquake motion.

In recent years, rising concern over the disposal of preservative treated wood has generated interest in the reuse and recycling of this biomass resource. The primary objective of this study was to evaluate the bending strength and stiffness of laminated crossarms consisting entirely of virgin wood, entirely of decommissioned chromated copper arsenate (CCA)–treated utility pole wood, or a mixture of virgin wood and decommissioned CCA-treated utility pole wood after treatment with pentachlorophenol (penta). The secondary objective was to correlate acoustic properties of the laminated crossarms with their mechanical properties. Solid sawn virgin wood crossarms, solid sawn crossarms cut from decommissioned CCA-treated utility pole wood, and the laminated crossarms were evaluated for strength, stiffness, strain, and acoustic properties. The solid sawn virgin wood crossarms and all compositions of laminated crossarms met the American National Standards Institute minimum strength requirement. Only the solid sawn decommissioned CCA-treated utility pole crossarms failed to meet the minimum strength requirement. Both crossarm composition and surface preparation had no significant effect on the strength of laminated crossarms. Maximum strain decreased with an increase in the number of utility pole wood plies in the laminated crossarms. Cubic relationships were found between stress wave acoustic velocity and the number of utility pole plies contained in the laminated crossarms. Both before and after penta treatment, a linear relationship was found between bending modulus of elasticity and stress wave acoustic velocity of the laminated crossarms. Penta treatment significantly reduced stress wave acoustic velocity for all categories of crossarms, both laminated and solid sawn.

The reusability of decommissioned treated wood is primarily dependent on the residual strength of the wood after service. Determining the residual strength can provide useful information for structural design and reuse of the decommissioned treated wood. This study evaluated the residual strength of decommissioned chromated copper arsenate–treated utility pole wood. Eleven decommissioned southern pine (Pinus spp.) distribution poles and pole sections were evaluated, using small clear samples, for bending strength and stiffness across and along each pole. Results showed that the strength of the decommissioned treated wood varied across and along each pole and among the poles. Average modulus of rupture (MOR) was 80.9 percent of the typical MOR of longleaf pine (Pinus palustris) virgin wood, and average modulus of elasticity (MOE) was 83.9 percent of the typical MOE. Average MOR of the samples in the outer surface (first test zone) was 7.5 percent lower than the average MOR of the adjacent samples toward the pith (second test zone) on each side of the pole surfaces, but average MOE showed no significant difference between the two zones. Older poles lost more strength in the first test zone. Results demonstrated that spiral grain substantially reduced the strength of utility pole wood.

The use of microwave (MW) technology is growing in all industries. This increased use has resulted from the high efficiency of converting electricity into MW energy; energy savings associated with rapid, in-depth heating of materials; specific interactions that can be achieved between MW energy and materials; radical acceleration of technological processes; reductions in MW equipment costs; and improvements in the reliability of industrial MW equipment. The new technology of MW wood modification is based on the supply of high-intensity MW power, up to 135,000 kW/m³ at frequencies of 0.922 and 2.45 GHz. Such power induces significant changes to the microstructure of wood and a dramatic increase in wood permeability. A number of commercial applications have been developed based on the fundamental changes in wood structure. These include the treatment of refractory wood species with preservatives, rapid drying of hardwoods, relief of growth and drying stresses in timber, manufacture of the new wood materials Torgvin and Vintorg, and modification of logs, sawn timber, and woodchips for pulping. MW equipment and processing parameters have been developed for three applications that are ready for commercial use. The technology provides significant material and energy savings and will give a new impetus to product development in a very traditional industry. The costs of microwave timber processing range from AU$22 to AU$69 per m³. These costs are acceptable to industry and potentially provide wide appeal for use in the timber, biocomposite, and pulp and paper industries.

Environmental accumulation of preservative adjacent to a chromated copper arsenate (type C)–treated wetland boardwalk was evaluated. The site is considered a realistic “worst case” because of the large volume of treated wood, low current speeds, high annual rainfall, and environmental sensitivity. Soil and sediment samples were collected before construction and 0.5, 2, 5.5, 11, 24, 60, and 131 months (11 y) after construction and analyzed for total chromium, copper, and arsenic concentrations. This article updates the findings after 11 years of exposure. Environmental concentrations varied with time, with proximity to the treated wood, and between riparian and aquatic locations. Concentrations of leached components in the soil developed slowly, were greatest at the 60-month sampling, and declined at the 131-month inspection. Soil samples with elevated levels of copper and chromium were confined to directly under the drip line of the boardwalk, and arsenic appeared to be limited to within 0.3 m (1 ft) of the structure. Concentrations of leached components in the sediments increased more quickly than those in the soil and tended to reach maximum or near maximum levels within the first year. However, concentrations of arsenic and copper in sediments directly under the walkway reached maximum levels after 60 months, before declining at the 131-month sampling. Elevated concentrations of copper, chromium, and arsenic were occasionally found in sediments as much as 3 m (10 ft) from the boardwalk.

Biocide retentions for copper-based wood preservatives used for residential ground-contact applications are established through field stake tests using small research stakes cut from selected sapwood and then treated in laboratory cylinders. The results from the relatively short-term field tests are then used to specify retentions for commercially treated timbers that have a range of densities and heartwood content. More than 120 4 by 4s that had been commercially treated with four copper-based systems readily available were purchased, with the posts carefully selected for good biocide penetration and a wide outer sapwood band, and analyzed for biocide retentions. Also, biocide gradients from five soluble copper and three particulate copper commercially treated 4 by 4s, all having the same labeled retention, were determined. All four systems gave a range of analyzed retentions, with some fraction of the timbers of each preservative system having a relatively low biocide level. In contrast to previous reports, the biocide gradient for wood treated with a soluble copper formulation was less steep than in wood treated with a particulate copper system.

A solid, crystalline fumigant (dazomet) with and without a supplemental copper compound was evaluated as an internal decay control treatment on Douglas-fir poles in two long-term field tests. Methylisothiocyanate (MITC), the decomposition product of dazomet, was used as a measure of effectiveness. MITC levels in the wood were above the threshold near the groundline application zone within 1 year after treatment. MITC levels above the groundline were much lower, suggesting that the treatment zone would need to be extended to produce protection in these higher zones. The addition of copper sulfate markedly increased MITC levels. Copper naphthenate was slightly less effective as a dazomet accelerant, but slightly better than dazomet alone. The results indicate that dazomet treatment remains at protective levels for 10 to 12 years. This range is well within the typical inspection cycle used by most North American utilities.

Severe windthrows often require salvage operations that can lead to increased costs. Given these extra costs, it is of paramount importance to make sure that wood degradation does not become so advanced that significant value loss is incurred. The rate at which wood deteriorates is a function of many factors, including species and climate.

The study was conducted in a northern area affected by two partial windthrows. Logs from the damaged area were collected for two species, balsam fir (Abies balsamea) and black spruce (Picea mariana). Logs were classified into one of three degradation classes based on visual assessments. A sample of logs from standing trees was also collected. In total, 167 logs were sampled. Each log was sawn and one piece of lumber was selected from each to determine the bending strength and stiffness and the visual grade.

The time since tree death, as determined from dendrochronology, ranged from 1 to 31 years. The visual grade of the lumber was not affected after 1 year but severe downgrades were observed after 4 years. Moisture content decreased rapidly for both species during the first year and continued to decrease until 4 years after mortality. No clear decrease in bending stiffness was identified even though such a tendency was noticed for older black spruce windthrows. Bending strength became variable after 4 years for balsam fir and was reduced after 4 years for black spruce. Windthrows older than 7 years will produce low visual grade timber of reduced bending strength and possibly of lower bending stiffness.