Need help with Timber Frame plans

[Kamposs]

I am looking to build a simple post and beam carport for my mobile mill and my tractor this spring, and was wondering if I could get some help with the plans. The past few years I've been using a plastic hoop house, and the snow destroys it every winter (I live outside Boston). I've been lurking around these forums for a while, always looking at plans/builds on this site and thought this would be a good place to post it. 

I will attach some pics of my design below from SketchUp. 

The concerns I have are - 
1/ Timber sizing - my design shows 8x8 posts/plates, and 6x7 tie beams, but likely overkill? I would like to extend this down the road possibly to 100' long.
2/ Scarf joint (?) - I wont be able to get a 32' log, so I am curious if scarf joint is the easiest way to continue a Sill Plate or other options. 

The tie beams going the length of the structure are there for a lean-to I would like to add down the road. My joinery is pretty basic, mortise+tenon posts, shouldered mortise+tenon for the tie beams. I will include braces on all tie beams.

Any help/advice you can give me would be greatly appreciated! If there is any more pics or information needed, please let me know.

Thanks in advance!




 

 

 

[Jim_Rogers]

You'll have to size the plates for the load they will carry. This will take some research. You need to know your snow load for your area. there are charts online that will show you the loads. 
Next you need to figure out if the rafters are big enough.
There is a story here about how to figure these things out:
42x28 w/12' Lean-to's and full 2nd story in TF plan and drawing depository (forestryforum.com)
see if this will help you to understand how to figure things out.

Also your rafter to plate connection is wrong, as the rafter notch can not be in the middle of the rafter. it has to be lower. No more than 1/4 to 1/3 up from the bottom.

Good luck with your research.

Jim Rogers