Expert: Dan Griffin - 3/13/2009

Question
I am planning on building a 36' x 48' x 10' or 12' barn and I am considering 2 options

1.) A pole barn using perma columns with 4 2x8s laminated posts. The walls will be 10' or 12' high  and I plan set the posts 12' and use a beam made of 4 2x8 sandwiched  between 2 2x12 and carriage bolted together. I will rest the 4x8  beams  on the posts and carriage bolt thru the 2x12 and 4x8 beams.  For the roof I will use 9/12 attic trusses on 16" centers with a standard sheeted and shingled roof. I would need a 30 PSI live load and I live in snow country. My question is are the beams proposed able to handle the load of the 2nd floor and roof.

2.) My second option is to use SIPs with a floating slab the rest of the construction would be the same.

Any opinions about which is the better approach would be appreciated.

Any info would be appreciated.  

Answer
Brian, I am not a structural engineer.  YOur columns and beams sound strong enough, but you really need to work out the details with a structural man.

Here are some accepted designs that might help:
http://bioengr.ag.utk.edu/extension/extpubs/planlist97.htm