Michigan Species of Timber Framing Logs?

[Woodbender]

Hi guys.

Question on species native to Michigan for cutting of Timber Frames. Oak is plentiful (shoot - we have 30" dia trees right here in our neighborhood), but what might be suited for long rafters and posts say 26 feet?

I don't mind mixing the wood species but they must be compatible in shrinkage and modulus etc.

I'm doing a lot of research at this point. I figure it's easier to ask questions and change design on paper than have the feces hit the rotating oscillator in the field.

I don't think I'd even mind buying my logs from others and cutting them myself if they were a strait trunk for timbers.  I'm looking for land in the northern part of Michigan's lower peninsula for cutting my own trees but I know full well that I might not find all I need on my own land for good long timbers.

Comments, observations?
Thanks gents

[Thomas-in-Kentucky]

As long as you don't need too many of them, oak logs can be found in those lengths.  (I used about a dozen of them that length for my house).  Typically, the logs are still that long when they're dragged out of the woods.... and some are even straight!    Getting someone to buck them and haul them to you in those long (over 16') lengths might require a little searching, regardless of the species.

If you were to mix woods of varying strengths and design for the weakest species a little bit of "over-engineering" might result, but that really ain't a bad thing.  As for shrinkage, that could be an issue, but even if you use one species in the frame, the wood could vary almost as much within the species as it would vs. another species.  For instance, some of the oak will be a lot denser and heavier (genetics and environment?), and it will be difficult to guarantee that all of the timbers have same moisture content when you get around to raising the frame (timing).  If the project is small enough, or if you have enough help, then what I say is not necessarily true. 

By the time I got around to raising my frame, I had two year old 8x8's that measured 7.75" next to freshly cut 8x8's that measured 8.0".  (These were white oak sill plates) The dilemma was then - do I cut the wetter 8x8 down to the drier dimension?  Nah, I just put them together and hope they shrink to the same size in a few years.   :

[Raphael]

If I were building in your neck of the woods I'd be looking to use Ash before it's all gone.  :