Treesearch

Some building codes require wood shingles to be fire-retardant treated. Because exterior fire-retardant treatments are subjected to weathering, treatment durability and leach resistance are critical for insuring adequate fire protection. We examined the effectiveness of various fire-retardant treatments on wood after 0, 2, 5, and 10 years of outdoor exposure. We used a Class C burning-brand test (ASTM E 108) and a Schlyter flamespread test to evaluate effectiveness. Most shingle treatments evaluated were either pressure impregnated or coated at the Forest Products Laboratory; however, a...

In 1982, 175 softwood plywood plants operated in the United States with a combined production capacity of nearly 23.1 billion square feet (ft2 ) (3/8-in. basis) per year, 60 percent greater than in 1965. The West was the region with largest capacity in 1982--12.5 billion ft2. The South had 10.5 billion ft2 and the North less than half a billion ft2. Approximately 1.1 billion cubic feet (roundwood equivalent) of peeler logs were consumed in 1982 to produce 15.1 billion ft2 of softwood plywood. Domestic softwood plywood consumption in 1982 was 14.6 billion ft2, with residential construction...

Large amounts of lumber and wood panel products are used annually for the repair and remodeling of residential structures and properties in the United States. In response to the need by government and industry for detailed information on this important market for timber products, a study was conducted by the Timber Demand and Technology Assessment Research Work Unit of the USDA Forest Service at the Forest Products Laboratory, Madison, Wisconsin, and the Wood Products Promotion Council, with additional support from the American Plywood Association, Tacoma, WA. Results of this study...

This paper reports results of a cooperative study by the USDA Forest Service, Southern Illinois University at Carbondale, and Tuskegee Institute. The study was designed to provide statistically reliable information on national and regional use of wood in pallets, by species and pallet type. An estimated 17 fbm of wood was required to produce a finished pallet; the finished pallet contained 12.7 fbm of wood. This is less wood per pallet than had previously been thought. Significant differences in wood use exist between regions. Pallets from the Northeast and North Central regions contain...

The Hoffman Run bridge, located just outside Dahoga, Pennsylvania, was constructed in October 1990. The bridge is a simple-span, single-lane, stress-laminated deck superstructure that is approximately 26 ft long and 16 ft wide. It is the second stress-laminated timber bridge to be constructed of hardwood lumber in Pennsylvania. The performance of the bridge was monitored continually for approximately 32 months, beginning shortly after installation. Performance monitoring involved gathering and evaluating data relative to the moisture content of the wood deck, the force level of steel...

A previous paper presented a reliability-based model to predict the strength of glued-laminated timber beams at both room temperature and during fire exposure. This Monte Carlo simulation procedure generates strength and fire endurance (time-to-failure, TTF) data for glued- laminated beams that allow assessment of mean strength and TTF as well as their variability. This paper reports an effort to validate model predictive capability through an independently fabricated set of 21 glued-laminated beams. Based upon the available data for the model input parameters on lumber strength and...

From a starting universe of approximately 1,300 Canadian and American sawmills, 149 were permanently closed between 1996 and 2003. This figure does not include small portable or part-time operations. These mills represented 17.6 million m3 of capacity, nearly 12% of the 1995 industry total. On the other hand, 25 new mills brought on-line have offset 4.9 million m3 of lost production potential. Further, upgrades to existing sawmills have added 31 million m3 of capacity. The region most severely impacted by closures was the U.S. West, which accounted for over half of all the capacity lost....

Estimates of the amounts of lumber and plywood used in constructing nonresidential nonbuilding structures in 1982 are presented. The market is stratified by six construction types. Lumber and plywood use is stratified by two end-use categories. Total lumber use is estimated at 507 million board feet. Total plywood use at 362 million square feet (3/8-in. basis). Estimates of lumber and plywood use in nonresidential building construction are presented in a separate report.

This report presents estimates of the amounts of lumber, glued-laminated lumber, trusses, plywood, particleboard, hardboard, and wood shingles used in new nonresidential building construction in the United States. Use of wood products is shown for several building types, project sizes, and building components. The estimates are based on a survey of 489 projects under construction in 1982-84. Lumber and plywood used per $1,000 of construction were 26 board feet and 21 square feet, respectively. These figures represent an increase over levels reported in 1969.

For international trade, heat sterilization of wood products is often required to prevent the spread of insects and pathogens. Application of heat sterilization requires estimates of the time necessary to heat the center of the wood configuration to the temperature required to kill the insect or other pest. The nature of the heating medium was found to have a significant effect on heating time of slash pine lumber. The heating time increased exponentially with wet bulb depression. When the wet bulb temperature in the heating chamber was below the desired center temperature, heating times...