Here are some resources for this issue:
- General information is available in the ASD/LRFD Manual. The longitudinal direction shrinkage (from green to oven dry) for normal wood usually ranges from 0.1 to 0.2 percent of the green dimension. For the radial and tangential directions, there is an approximate 1% change in dimensions per 4% change in moisture content.
- USDA Wood Handbook Chapter 4.
- WWPA Shrinkage Tech
- Canadian Wood Council's "DimensionCalc" will calculate for the dimensional change in wood due to shrinkage