PT wood foundation

[new land owner]

I am starting a small building 16 x 24 in the spring and I am trying to make a decision on the foundation.  I was wondering if anyone has poured a footing and then built a 4' foundation wall of PT lumber and then framed on top of that? I am in the north country and would need to insulate to keep out the cold?

Thanks

[jb52761]

Don't have an answer for you right now, but welcome to the forum, and you're in the right place if you want answers.....haven't had time to ponder your question.....hang in there..........

[peter nap]

I haven't done one but wood foundations like that aren't uncommon. The big problem you will have is finding foundation grade treated lumber that doesn't cost mote than gold plate.

[glenn kangiser]

I think one of Johns plans has an option for a complete pressure treated wood basement if I recall correctly.

[John_C]

I watched a few of them go up years ago.  They were built over a compacted gravel footing not poured concrete.  I believe the concrete would hold moisture against the wood so gravel was preferred not to mention cheaper.

Back then, when CCA was the preservative of choice

Lbs. per cu.ft.    Use
0.25                Above Ground
0.40                Ground Contact
0.60                Permanent Wood Foundation
2.50                Salt Water

I don't know what the standards would be for todays treatments.

[TheWire]

You can still get CCA 0.6 treated wood for use in permanent wood foundations (PWF).  My local lumber yard in WI found reasonably priced CCA wood in MI.  Its stamped "For PWF use only".  Normally PT wood foundations are set on compacted gravel footings instead of poured concrete.  I'm building a 20 x 32' 2 story and I am using a PWF crawl space of 2' walls on top of 16" wide by 16" deep gravel footings.  I'm very happy with this foundation so far.  I'm taking steps of a well drained site, footing drainage, keeping run off away and insulation to prevent the frost from moving it.