Pole barn posts

[Handyman]

I have a little bit of a delema here and would like some input...

The only place I can build my barn is where there is a slight slope to the rear, about 18" over a 40 foot in one corner and about a 2' drop in the other rear corner. The wall height is going to be 13'6" to 14' high. I'm looking at an aprox size of 30x40'

There two options I' looking at...

1, building a retaining wall and back filling in and anchoring the post or build the wall on top of the concrete.

or

2, considering cost, possibly setting posts in the ground and building a form and pouring concrete between the posts to make a retaining wall and then back filling in in order to raise & level the ground and then pouring the concrete floor.

I have also took into consideration about the pressure treating process in that anything over 2" thick doesn't get properly treated throughout the the thickness of the wood, so I was also considering using 2x6's and making my own 6x6's using a staggered pattern which will also allow me to make them as long as needed.

Has anyone used either technique ?

[jml755]

I'd probably go with Option 2. Not sure if your Option 1 meant only the back wall on top of the slab, but I wouldn't mix construction methods (buried poles on the side & on-slab at the back).

I'd make sure the retaining wall is 2/3 buried & 1/3 exposed with re-rod throughout, so that would mean about a 6' wall if you've got 2 ft exposed. That would also put you below the frost line here in Michigan and I'm sure it's higher in TN. I'd also do a monolithic pour with the back retaining wall/foundation and slab to avoid issues with the wall "sliding" out from the slab. I've seen a retaining wall that I understand was about 50/50 buried/exposed leaning over some so I'd be overcautious in the design. One recommended feature is the use of tiebacks (rods/plates going into the backfill) so that's an additional option.

I'm not a structural engineer so the above is just what I would do if it were my barn. Take it for what it's worth to you. [img]/forums/images/icons/smile.gif[/img] Good luck and post back with pix with what you did, if you'd like. It's always great to see examples of construction on the site.

[tallyho8]

I know this is an old thread but just in case someone reads this and is thinking about using three 2x6s to make a 6x6 post to stick in the ground:

6x6s are heavily treated for inground usage. Most 2x6s are lightly treated for above ground use only. These would rot out very much quicker in the ground than a 6x6.