Misc/Chat Building a root cellar?

[ShadowMan]

We live in the mountains in Southern California at about 5,500ft. Our Hardiness Zones are 8a 10°F to 15°F: to 8b 15°F to 20°F. As with most homes/cabins here our place is built on a slope and is essentially four stories tall...with the bottom most floor is unfinished with a dirt floor and here is called the "Build Up". This is where the foundation is, it's sloped, but could be dug out as everything is inside the foundation walls. As mentioned the floor is dirt. Well, dirt and rock. A lot of rock.

What I'm considering is digging out an area in the build up and creating a root cellar there. Essentially what I'm starting with is a sloping earth floored basement. Has anyone here done something like that? The current floor slopes from north to south. The northern wall would be completely up against the soil, while the easteren and western walls would only be half covered by soil and the southern fully open and up against the outside wall of the lowest floor.

I'm debating on what material to use to build this root cellar: Cinder Block, treated wood stud frame and marine plywood heavily insulated, or even those foam forms that you stack and then fill in with cement. Wood might be out of the running right now due to the astronomical cost these days. I am also considering pouring a concrete pad as the floor, with a drain in the middle, or maybe an all gravel floor would be better? I want it large enough to store an entire seasons worth of the garden in for two to four people.

I welcome any advice, experience, ideas, links and suggestions.

 

[Samuel Adams]

I buried a large steel bulk tank.....11’ diameter, 19’ long, 5/16” wall.

Laid horizontal.

Filled the bottom 3.5’ w/pea gravel then 4” concrete over that.

Used a smaller tank, 5.5’x12’ long for the entrance tunnel.

Had I more operating capital, I would have poured an 8-10” concrete shell, heavily reinforced, over/around the tanks, to create a 150+ year structure....but that has yet to happen.

A top vent is important for humidity control and the elimination of warmer air to allow cooler air in when it’s available.

Bury as deep as is practical for maximum earth cooling/temp stabilizating.

If your climate is dry, dirt floor would be fine.

 

[Raggedyman]

hey Doc
I did something very much like what you are planning about 2009. wanted a 10 X 10 cellar . . . dug into a bank and layed up 12" bloc poured solid - corners reinforced with rebar on a footer. roof is 8"poured; all that was waterproofed and covered w/ 3-5' of earth. there is foundation drain all around and a 4" floor drain in the center in the center just in case. the floor is typical 3/4 washed gravel - like you'd use in a drain field. as Sam said - vents are important - there is a 6" pvc vent at the floor and a 6" vent in the roof centered at the ridge. both vents have typical chimney dampers like you'd run on a wood stove. its a little damper in there than I'd like on occasion but there's wet weather springs all over these mountains . . . you probably have the same situation there.

hope that helps to give you some ideas

 

[ShadowMan]

Our mountain is pretty dry most of the year. Snow in the winter of course, but not a whole lot of rain. Not sure how I can get and keep one section of the root cellar humid enough for the veggies that require that. Dry is not a problem. I think I'll need two rooms, one humid and one dry for the things that need it and shelves of canning jars.

Lots of research left to do. THANKS for your ideas and suggestions!!

 

[Orion Commander]

Do you have an extension service from the University system in your state? Iowa has such as well as several other states. Our extension service is a wealth of information.

 

[AlaskaSue]

I’m going to do an experiment this winter with freezing produce and fish in the permafrost here (but I’ll have it very clean). It’s not that far down, even though ‘global warming’. I hope to report next spring how it goes. I do have a hillside I can dig into if this experiment works out. Might be a good site for other purposes in a nuclear world…