Sizing posts for pole barn

[UncleBuck1]

There are lots of pole barn threads here, and let me apologize in advance if my question has already been addressed in one of them!

I'm planning on building a 36x48 monitor style pole barn, with post buried 4' in concrete over pea gravel footings and 12' spacing. Based on what I've read 6x6 posts are most commonly used in this type of layout; what's different in my case is that I plan to use the loft area above the center section as a bunk house which will increase the load carried by the posts.

So, to cut to the chase, I'm looking for some guidance on what size posts I should use.

Brian

 

[RedNeckRacin]

Well some more information would be helpful, Are you going clear span? What kind of uplift/wind loading do you have? Im assuming that since your in LA that you dont have snow loads to worry about. What do other people in your area have for pole building specs? Do they have any complaints? Im thinking that your footings might be a bit small and I'm also thinking that 12' spacing is wishful thinking with a 36' span assuming that is the way your going to run your trusses. For instance, we have an 80'x100' building with 6"x6" posts and no bunkhouse and they are on 8' spacing.

 

[UncleBuck1]

Well some more information would be helpful...

Fair enough! I will NOT be clear-spanning the 36' width; my plan is to space the posts at 12' centers across the width of the barn as well the depth so no span will be more than 12'; picture a tall 12x48 barn with 12' sheds on each side. Snow load is not an issue at all down here.

 

[Beltzington]

Other than your dimensions you're basically building the same structure I would like to build sometime in the next couple years. I am curious if you have checked with the county building permits folks? Because you will be living in upstairs they might consider your "bunkhouse" an "apartment" which requires a permit, if so you can be sure they will be very specific about material and layout. Also, for other projects I have just dropped by the building permit office and they have always been friendly and helpful answering my questions. Good Luck and let us know what you decided on and how it works.

 

[Rustyiron]

You should be good with the 6x6. I prefer to use the laminated posts available at a post frame supplier, they stay straighter and are avalilable in many legnths. The bottom (burried) portion is treated better than a 6x6 can ever be. You might consider these perma column (see pic) or check out http://bse.wisc.edu/Bohnhoff/Publications/FSBS-1993-Post_Frame_Building_Posts.pdf
If rot & termites are an issue in your area, the cement "perma column" is a good investment. Treated lumber will only last so long.

 

[Bigkrank]

Titan Timbers - Glue Laminated Wood Columns - Post Frame Construction Products

 

[PoleBarnGuru]

Brian ~ I will make a single recommendation which will make your life far less complicated and will assure you get a building design which will both adequately carry all of the loads, as well as not unduly waste money on needless materials.....Purchase a complete pole building kit package from a company which can provide plans specific to your building and its loading requirements, provides detailed instructions, and delivers the materials to your site. The plans should be ones which the company can provide engineer seals on and calculations for, at a minimal charge. This tells you it is the same building, whether engineer seals are provided or not.