blownz281

Thanks guys. Have a local guy on craigslist that has some 6*6 and I think he said RR ties. Hopefully they are good enough to use. I have a bunch of bricks laying around I want to put underneath them,to keep the wood off the ground.

Olaf - if you look at harbor Freight's website the 6ft-8ft greenhouse is what I am getting. I don't want the metal laying on the ground. Being coastal and hurricane season being August-September I would need some way to secure it and be able to remove it if I had too.

pmurphy

I am not sure what material your greenhouse if made of but it is mostly likely polycarbonate panels, and I found that these greenhouses are not that heavy. Once set up they can easily be moved by one person (just clumsy) so you may not have to worry too much about settling; if anything, your 4x4's will probably weigh more.
I would simply dig a trench into the soil and lay your pressure treated 4x4 in this trench, making sure they are level at this time (once you get below the first couple of inches of soil is should firm up). You might even want to do a second level and bolt them together (I use 2 layers of landscape ties that were "overlapped" at the corners and then nailed together - usually cheaper than 4x4's and already treated). I then bolted the greenhouses onto the ties and placed a couple of layers of landscape fabric inside with rocks to help prevent weeds etc from growing.
I have found this worked for both of my greenhouses, one of which has been set up for almost 5 years now.

blownz281

Thanks

pmurphy

FYI, the reason I suggest digging a trench for your 4x4" is that the frame of your greenhouse will most likely create a "box" - meaning that if you attach it to the 4x4's it will raise the bottom of the door that same height and create a sill that you will have to step over. Not the biggest worry, you just have to remember to "step up" - which took me a couple of weeks and banged shins to remember with my first greenhouse (the second one sits at ground level). Your biggest issue will be if you are moving large or heavy things in or out, they will have to be lifted over the sill.
Pam