I am working on a log home project and I just discovered that there are grades and design values distinct and seperate from those published in the NDS that are used just for "Structural Members Used in Log Building." I am aware of ASTM D3957 which is a guide to establishing the grades. I have not been able to find who the grading rules writing agency is or who publishes the design values for the established grades in the commonly used log species. Any information would be greatly appreciated.
Thank You
P.S. Would these grades and values be more appropriate than those in the NDS when designing pole rafters in a timber frame? What about those cruck creations of Mr. Sobon and others?