No small local mills around. There are at 8 or 10 around here cuting Pine, Poplar, Red Cedar and what ever they can get. I can buy it at a small mill less than 2 miles from my place.

We used interlocking bricks. We drilled each brick and put an anchor in the hole. Then drilled holes in the metal base and put the screw in through the metal, then into the anchor and tightened it down. It was very labor intensive. I wanted to use wood, but my husband insisted, he worries about termites and wood rot. It seems pretty solid. But we don't have weather extremes here except an occasional santa ana wind.

I'm not much help, since we did use pressure treated wood for our foundation. I just wanted to mention that I don't think those threads have been removed...GardenWeb has been doing some work on the site, and they're still having problems with using the search engine to access older threads. I'm having the same trouble. Hopefully the search function will be working better in the future...

Thank you all for your replies and input. It looks like I'll probably being going with 8' cedar 4x4s that I'm going to have to splice together. 10' lengths are twice as expensive as 8' and redwood is way to expensive. I toyed with the idea of concrete block/bricks but think wood will be more user friendly. Pine' out because of the "rot factor".
Thanks again!!

An update on my foundation search. We were planning on using cedar for the base but were not too impressed with it's 4 year or so lifespan so to speak. During our search we found a source for Juniper. Less costly that cedar and extremely resistant to bugs and rot. Just an FYI for any of you that do not want to use pressure treated wood. Mudhouse, I want to thank you for your blog/link and the extraordinary amount of information and help with the instruction/setup on the HFGH. It's amazing. THANK YOU!!!

gponder, thanks, and glad the blog helped! It's just a way to pass on some of the great info stored here in many previous posts and photos. I love how forums like this allow us to help each other.

Thanks for the tip on the juniper!

If you want your base to last and not cost a fortune, buy treated 4 X 4's. Dig a narrow trench about 6" deep under where you will lay them and fill it with gravel for drainage and secure them down by drilling holes for some lengths of rebar, driven at least 2 ft. into the ground. If it's allowed to drain, treated will outlast cedar by a long mile. Just don't install the rebar where the screws will be for the GH base.

Then, because you don't want the aluminum to contact the copper treated timber, lay a barrier between the timber and the bottom sill and for that, one material that would work well and last, is vinyl siding. Most home centers sell cheap vinyl siding by the piece and just 3 pieces (they are 10' long) will give you all you need. Cut them to the width of the timber, lay the strips atop the timbers and install the GH sill over it.

The caveat on a HFGH is the same as it is for any other structure: first get your foundation dead level and well secured before you start erecting the GH. If it means extra time and grunt work- do it- because the one thing you DO NOT want to have to retrofit is your foundation.

BTW: If you want to burrowing critter proof your GH, now is the time. Lay some 1/2" hardware cloth just under the timbers and out about 2 ft. and stake it down around the entire outside perimiter. The critters try to dig in only at the base and haven't the smarts to back off to the outside edge of the wire.

Birdwidow. Thanks for all of the great info. I cannot use treated lumber, that was my original dilemma. So glad I found the juniper though. There are still juniper fence posts standing that are 50-60 years old in eastern Oregon!
Thanks again for the other info. Can't wait to get started. Wish it would quit snowing!

I'm not sure why you can't use treated, but if the fir will do for you, by all means- use it.

But do think about the critters and their slithering predators, BEFORE you seal your foundation. I admit that I'm sort of freakish on the subject, but mice can wreck havoc in a GH and while I generally have no issue with snakes, I prefer they do their hunting elsewhere.