Foundation help, treated or no??

[DocGP]

Looking for advice here.  Leaning toward treated, but wanting to cut my own if possible.   Starting to plan for a little off grid cabin (12X20) on family property next to a 6 acre pond, so land is uneven.  My plan is to sink sonotube and leave it to project 12-16" above ground, put the Simpson 6X6 anchors, then 6X6 to finish the pier, and two 6X6 beams.   At least that is what is in my head.  Would you use treated pier and beam or with the concrete sticking above the ground, would raw wood be acceptable??  

Any thoughts would be appreciated.  

Doc

Offsite photo deleted by Admin

[stanmillnc]

I have used the exact Simpson strap post bases you show pictured in the last two structures I built - one a post / beam barn and the other an outdoor kitchen pavilion. I used all wood I milled myself - none of it treated. As long as the metal on the bottom of this fixture where the post rests is not sunken into the concrete, you are fine to use untreated wood. I install mine just a little above the concrete and make sure it doesn't sink below the concrete surface level as it sets up. This has worked great for me with no observable decay on the post ends for ~10 years now. Concrete is hygroscopic, so If your post ends are directly on, or in the concrete, the wood end grain will absorb the moisture from the concrete like a wick and your untreated wood will eventually rot.

[Hooterspfld]

I'd go the, "better safe then sorry route." Use treated and 5 years from now you can't second guess yourself. Plenty of other ways to use wood you mill yourself elsewhere to accent the build. 

[Don P]

If this is a habitable structure a pier and beam foundation is technically engineer required, they have a rich history of failure. Braced walls go over braced foundation walls. Girders closer than 12" to grade or joists closer than 18" are treated. A 6x6 is graded as a post and is rarely capable as a beam.

[kantuckid]

My off-grid cabin I'm using 6x10", white & chestnut oak beams on concrete piers cast in sono tubes set on plastic square foot form bases. HD sells them and they ship to your door free! My beams are to be bolted. I see no mention of a termite shield which I think Texas has them?  :D
I've seen plastic and metal shields and leaning toward metal as I already have some.
They say that even PT wood gets termite damage so that part would scare me enough to use them.
My beams will be fastened via foundation bolts then 3x5" steel angle brackets-beams to concrete. Since my cabin is using log walls I'll go with the standard of a minimum 2' splash distance to my wood parts from grade. Under my cabin I highly suspect that those oak beams will last a very long time not exposed to weather. Longer than me huh?...
BTW, there an old post here under my name, with some great comments on wall loads in a cabin build