Root Cellars?

[SkFarm25]

Interested in digging a root cellar in the spring. Unfortunately I don't know much about root cellars. My great uncle has one dug into the side of a bank, but that's not really an option for me so I'll have to dig straight down. We had a brutal winter last year and he didn't have anything freeze in his, we were getting vegetable from him all year,so I really want to make one. So mine will have to dig down on flat land. I would like the finished product to be a room roughly 8x8 or 10x10. My questions are How deep do I need to dig it? Do I need to go below the frost line? How much earth needs to be on top? Best way to keep walls and roof from caving? Hoping to do this as cheap as possible so Id like to stay away from cement if I can. I have access to the large railroad ties so I was thinking of using those as much as I can. Ideally the only thing id like visible from outside is the stairs going down. Keep in mind our frost line is 8-10 feet too.

[Jack of all Trapping]

Well,your frost line is really deep. I built a cellar. It is 8x8. I had a backhoe do the initial digging. It is in the side of a hill and the door faces north. It is 7 feet from floor to ceiling. About 6 ' of the entire structure except the north wall is underground with approx 21/2 foot of ground mounded above it. I built it with concrete block. I poured a concrete footing all around and then raised the block. Ventilation is the key and drainage on the outside. I also put in a floor drain. I have air coming in from the open wall side where door is. It is at the bottom. I then have a pipe at the top to let stale air and vegetable gases out. The floor is 8 inches of gravel. Not concrete. The top is a poured with rebar also. I made a pretty elaborate form for this from 3/4 ply and 2bys. You want moisture in your cellar,but not too much. This will cause mold and fungus. I have a moisture meter and thermostat inside. My cellar works very well. I have never had a issue with too much moisture. I sometimes pour some water on the gravel floor to keep it where I need it. I have seen some cellars with concrete floors and in the Spring they flood. The entrance is 2 doors. The 1st one traps the air. The 2nd one is insulated with 4 inches of insulation inside and out. No windows. I copied the design from my Grandpops rootcellar at the farm in Austerlitz N.Y. They never had a problem. If I find a way to put pics on the forum.I will. I miss that. I switched to a I Pad and haven't figured it out yet. Do you have a basement? I have a couple neighbors on farms up here that have built rootcellars in a portion of them.Saves time and a LOT of money.
  Peace.  Jack

[SkFarm25]

I really only have a pantry in my basement under the stairs, its insulated and has a 4 inch abs pipe venting it to the outside. Works well but its too small to really put a lot into. I have free access to railroad ties and backhoe so I was hoping that would take care of most of the expense, but like you said my frost depth is going to be an obstacle as well, thanks for the reply!

[northwoodstrapper]

You might watch using the treated railroad ties. Your open stored fruit and veggies might pick up a gnarly taste.