The Log Wall Performance Estimator (LWPE) is a report that describes and analyzes a specific log building system (a specific log profile, wood species, and moisture content). It reports the performance of an individual log profile in a manner designed to assist outside engineers and code officials evaluate the building system, help refine product development, and provide designers with critical capacities to be considered during plan layout.
The first page of the LWPE report provides the properties of the log profile — section properties, grading criteria and associated design stress values,settling allowances, the wall’s fire-resistance rating and thermal properties, while the following pages of Section 1 report the capacity of the log wall as an assembly.
The report also includes design capacities for the log in simple span conditions (e.g., headers, interior girders, etc.), and provides information relating to fastening options.
The LWPE provides design limitations for layout of a log structure in a form that can be used by designers during the creation of the plans. It includes:
- A log profile sheet with an illustration of the wall-log
- The wall-log properties are coded to the respective ICC400 sections — section properties, weight, visual grading criteria, design stress values, average wall thickness, thermal value, fire-resistance rating, and settling analysis.
- Load tables showing the structural capacity of the wall-log in both horizontal and vertical load paths, expanded to demonstrate allowable loading (plf) for 7 spans.
- Span tables present the maximum allowable spans (simple) for wall-logs used as headers, beams or girders — 3 structural grades, 1-, 2-, and 3-course configurations of full span logs.
- Span tables and fastening schedules are included for built-up and bolted together log headers/beams where splice/butt joints are permitted within the configuration.
- A presentation of the estimated performance of the log wall as an assembly in response to horizontal loading.