We use white oak for a considerable number of frames (we have a local supplier of high quality logs.) It does shrink and move around quite a bit, and, pretty much requires the use of a boxed heart timber of anything of substantial size. It works awesome green, and, is easier than most other hardwoods when dry.
It is quite rot resistant, and, there is quite a historical precendence of using it in frames. My one gripe, as an engineer, is that it isn't very stiff. Longer span floor joists / purlins etc can be hard to justify.
Red oak is stiffer, but, not as rot resistant.
Hope this helps,
Joe
