Question regarding timbers drying/bowing/warping etc...

[Daburner87]

Forgive me friends, but I have questions. 

I'm planning on putting some fresh sawn 8x8 and/or 6x6 timbers down on top of some level bases spread 8ft apart.  Each timber will be 8ft in length.  Do I have to worry about these timbers bowing or warping? I'm trying to use mostly white oak for the base, and originally I was going to put the bases 6ft apart, but I really want to go 8ft lengths to dig less holes. Also how many inches of each timber should sit on each base? 

I'm kinda doing an unconventional shed/workshop build. The log guy I use just told me he can only do 8ft lengths which really changed my plans.  I'm building an 8x24 lean to shed. I wanted to go bigger but not sure I can get the logs I need now.  

[Brad_bb]

If you want longer, why are you locked into this one supplier?  

Boxing the heart is a must with pith centered in both directions.  Majority should stay relatively straight, but oak can have a mind of it's own.  Depending on the stress in the log, it will follow that when drying.  I have a 25ft tie beam and the last 5ft veered off of straight by 2.5 inches.  Others stayed straight.  Some may want to twist end to end.  They will check on one face and the opposite face will shrink and have a smaller dimension than the checked face.  Don't forget to end grain seal your beams with Anchorseal.

[Daburner87]

Well the local tree companies are willing to drop these logs off for free, but my main guy had too many problems with his log loader they got rid of it and now they only pick up 8ft lengths.  Waiting to hear back from another supplier, but these guys have to pay to dump these, so they drop them off at my house for free.  I don't pay for logs.   I have an entire week off so I'm about to just get the 8 footers so I can get started on this project.