Root cellar

[redman2006]

Anyone build one? What style and construction methods did you use?

Thanks

[Cwi555]

Reinforced concrete

Anyone build one? What style and construction methods did you use?

Thanks

I've built several for myself and others. Reinforced cinder brick with arch or flat roof, reinforced concrete pour, large diameter concrete culvert both square and round, even a couple that used rejected wind tower segments (rejected for wrong material but still worked for this purpose).

The one constant between them was the use of bitumen to seal them though that is not always necessary depending on materials and where they are going.

A word on the culvert. Some folks turn it down due to upfront cost only to find it cost more in time and or money by the time they go through screwing with it. For them, digging out the side of a hill, compaction, and sand/stone prep was the most technically complicated part of it. The rest is dead easy.

A word on cinder brick, it's the cheapest form. However if your not skilled at laying a concrete pad, bitumen protection, laying the brick, or arching the ceiling, might want to just have it done.

There are so many variables involved that I hesitate to recommend one specific method.

[Sacajawea]

Why specifically an arched roof, cw?

The old root cellars I've are 2 story, built into a hill - and the 2nd story is either shed or canning storage; sometimes summer kitchen.

[Cwi555]

Flat roofs don't distribute loads very well. Stresses have no way to travel, rather they end up concentrating in the center.

Why specifically an arched roof, cw?

The old root cellars I've are 2 story, built into a hill - and the 2nd story is either shed or canning storage; sometimes summer kitchen.

[Cwi555]

Been trying to think of a good example.. next time your in a Sams, Costco, or Walmart look up. All of them are flat roofed.
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Take note of the spans, materials, and nature of the same. It's all about distribution of load.
Both the Romans and the Chinese had that engineering down to an art.

Unless you're talking 6 foot spans, or next to no load on top (dirt backfill for instance), an arched roof will do a better job. The kind of roofs as pictured are not something you can put a heavy load on. One of the reasons it's not wise to bury a sealand container btw.

[Sacajawea]

OK, I thought there might be another reason. For instance, shedding water down to the base or something.

[Cwi555]

OK, I thought there might be another reason. For instance, shedding water down to the base or something.

That is a secondary benifit, but not the primary purpose. If it's saturated dirt, the load will be significantly increased.
Assuming tightly compacted earth around it, buttressing is minimal.

http://www.architecturecourses.org/flying-buttress

gothic_church_digram.gif
However, tanks an semi trucks can be parked over the top of the thing with use of angular or flying buttresses.
Medieval architecture made use of them to hold up extremely heavy loads and high walls such as the case with the following;
84f86257c0f07fc66370d52cf6256649.jpg

Many such structures still stand close to a thousand years later, and in some cases, 2,000 plus years. Flying buttresses don't have to be stand alone either as they can be buried along with the rest of it.
If a person wants a larger root cellar, or other underground facility, it is the way to go. If it's something small, square works as insufficient area of stress acts as its own protection. For any structure I work on these days, I try to think long term expansion potential so generally go with an arch. Round culvert tube works for that as well.

Then again, just a hole in the ground works if the ground is of the right type.

[redman2006]

One suggestion was a large septic tank that was rejected due to chips.

Other sites suggest dirt or gravel floors to keep humidity up. There seem to be many suggestions.

We want one for storage, but also as a storm shelter as the home has no basement.

Depth was another issue. I don't know how deep to have reasonable temperature consistency.

The one I had in kansas was flagstone floor and native limestone walls.

Ventilation is another area the sites disagree. Some say a sealed door with ventilation high and low. Others wooden door but not sealed.

We have a very high water table. I am concerned with flooding or too much moisture in the wet years.

[Cwi555]

Most sites will disagree. Problem being the numerous variables involved. Two variables you mentioned here eliminate soft floors (dirt/rock), and for the same reason, high water table, The storm shelter purpose eliminates the wooden door along with high water table.
One size does not, in fact fit all, therefore the apparent inconsistencies you've noted between sites.

The particulars of your proposed site would have to be known to give any intelligible recommendation as a result (exact depth of water table, depth of bedrock, type/consistency/uniformity of the dirt, available material etc).

One suggestion was a large septic tank that was rejected due to chips.

Other sites suggest dirt or gravel floors to keep humidity up. There seem to be many suggestions.

We want one for storage, but also as a storm shelter as the home has no basement.

Depth was another issue. I don't know how deep to have reasonable temperature consistency.

The one I had in kansas was flagstone floor and native limestone walls.

Ventilation is another area the sites disagree. Some say a sealed door with ventilation high and low. Others wooden door but not sealed.

We have a very high water table. I am concerned with flooding or too much moisture in the wet years.

[DMH]

Totally out of context, but the talk of flying buttresses brings to mind "The Pillars of the Earth" a historical novel by Ken Follett. A great read if you are in the mood for a long read about the building of the cathedrals.

[Cwi555]

Totally out of context, but the talk of flying buttresses brings to mind "The Pillars of the Earth" a historical novel by Ken Follett. A great read if you are in the mood for a long read about the building of the cathedrals.

That is a good one. Been about 20 years since I pulled it off the shelf, but it inspired a lot of research on my part and some design elements for some shelters I've designed and built. Need to dust it off and read it again soon. I wouldn't say it was totally out of context for that reason.