Active Standard ASTM D3957 | Developed by Subcommittee: D07.02
Book of Standards Volume: 04.10
Historical (view previous versions of standard)
These practices cover the visual stress-grading principles applicable to structural wood members of nonrectangular shape, as typically used in log buildings. Both sawn lumber and round timber stress-grading methodologies are applied to two different types of structural members used in log buildings: wall-logs and round timber beams. The development of design stress values from clear wood strength values for wall-logs and round timber beams for used in log buildings is demonstrated in this standard. However, the grading provisions presented herein are not intended to establish grades for purchase, but rather to show how stress-grading principles are applied to members used in log buildings.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
1.1 These practices cover the visual stress-grading principles applicable to structural wood members of nonrectangular shape, as typically used in log buildings. These practices are meant to supplement the ASTM standards listed in Section 2, which cover stress-grading of sawn lumber and round timbers. Pieces covered by these practices may also be used in building types other than log buildings.
1.2 The grading provisions used as illustrations herein are not intended to establish grades for purchase, but rather to show how stress-grading principles are applied to members used in log buildings. Detailed grading rules for commercial stress grades which serve as purchase specifications are established and published by agencies that formulate and maintain such rules and operate inspection facilities covering the various species.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D25 Specification for Round Timber Piles
D245 Practice for Establishing Structural Grades and Related Allowable Properties for Visually Graded Lumber
D2555 Practice for Establishing Clear Wood Strength Values
D2899 Practice for Establishing Allowable Stresses for Round Timber Piles
D3200 Specification and Test Method for Establishing Recommended Design Stresses for Round Timber Construction Poles
ICS Number Code 91.080.20 (Timber structures)