AWC has links to historic documents on our website here: NDS Archives
Designers can view and download copies of the 1922 Design Values for Structural Timber and the 1944 NDS on this page. Archive versions of the NDS are also available for a small fee.
Ecourses are also available relating to evaluating in-service structures. Both DES140 – Structural Condition Assessment of In-Service Wood and DES160 – Evaluation of Recommended Allowable Design Properties for Wood in Existing Structures can provide helpful information to professionals working with existing structures.
See also: https://www.awc.org/faqs/general/where-can-i-find-information-on-evaluation-maintenance-and-repair-of-existing-structures