Treesearch

Three species of small-diameter logs from the Klamath/Siskiyou Mountains and the Cascade Range in southwest Oregon were tested for their potential for value-added structural applications. The logs were tested in bending and compression parallel to the grain. Strength and stiffness values were correlated to possible nondestructive evaluation grading parameters and compared to values derived from published values based on tests of small-diameter clear wood of the test species. For the test sample, specific gravity and static bending modulus of elasticity were good indicators of strength....

Wood is a biological material that has widely different properties depending on species, geographic area where the tree grew, the growth conditions, size of the tree at harvest, sawing, and other manufacturing processes. Some of the more important wood properties as they relate to wood finishing are discussed, e.g., growth rate, density, knots, extractives, juvenile wood, grain orientation, and weathering characteristics.

Because of performance problems with hardboard siding in southern Florida, the U.S. Department of Housing and Urban Development (HUD) proposed a local standard requiring prefinishing of siding and priming of all siding surfaces, including the back. However, the effectiveness of these practices was questioned. To determine if back-priming or factory finishing improves durability and performance of hardboard siding, we installed factory-finished and factory-primed siding on two buildings in southern Florida. The buildings were identical except that one had gutters and no overhangs and the...

Drying Hardwood Lumber focuses on common methods for drying lumber of different thickness, with minimal drying defects, for high quality applications. This manual also includes predrying treatments that, when part of an overall quality-oriented drying system, reduce defects and improve drying quality, especially of oak lumber. Special attention is given to drying white wood, such as hard maple and ash, without sticker shadow or other discoloration. Several special drying methods, such as solar drying, are described, and proper techniques for storing dried lumber are discussed. Suggestions...

To promote more efficient use of small-diameter timber, research efforts are being focused on the development and evaluation of connection methods that can be easily applied to non-standard round wood profiles. This report summarizes an evaluation of a bdowel-nut connectionc as an option for the use of Douglas-fir peeler cores in three-dimensional truss or bspace-framec structural applications. Joint details were selected on the basis of ease of fabrication, joint strength, failure mode, and cost. It was concluded that the cores should be dried close to expected ambient conditions prior to...

The productivity of U.S. wood and paper product output in terms of wood input is computed and displayed in graphs. Background tables provide supporting data. The productivity trend parallels trends in the recovered paper utilization rate. Recycling and wood residue use are key factors in productivity gains.

In bridge timbers, wood decay is usually found where water has accessed the end-grain surfaces. In preservative-treated members, end-grain surfaces are most likely to be those resulting from on-site framing cuts or borings. Because these at-risk surfaces are easy to see, it seems feasible to establish a program where diffusible preservatives are repetitively inserted into those critical areas spatially distributed in a grid and on a schedule that will ensure protection, thereby extending the life of the entire structure. The objective of this study was to determine the vertical and lateral...

Because of a combination of circumstances, there is an overabundance of small-diameter timber available in the United States. There is low demand for this material because it has low value. One way to increase the value, and therefore the demand, for this material is to develop or expand markets where the material can be used. We looked at markets where little or no machining would be required before use because this would make it more feasible to use small-diameter material. One such market is that of wood posts in highway applications. In this study, we gathered information on the...

Forests in the United States contain a significant amount of small-diameter and underutilized material. These overstocked stands not only increase the risk of insect, disease, fire, and drought damage, but also are costly to remove. Finding economical and marketable uses for small-diameter and underutilized material would alleviate these problems while improving watershed health and providing economic opportunities for local communities to help offset forest management costs. An extensive research program at the Forest Products Laboratory of the USDA Forest Service is focused on searching...

This guide was prepared to assist inspectors in the use of stress wave timing instruments and various methods of locating and defining areas of decay in timber members in historic structures. The first two sections provide (a) background information regarding conventional methods to locate and measure decay in historic structures and (b) the principles of stress wave nondestructive testing and measurement techniques. The last section is a detailed description of how to apply the use of stress wave nondestructive testing methods in the field. A sample field data acquisition form and...