Price/Stability of "just add water" concrete?

Question

Hi, bit of an odd question, im planning to build something like an underground bunker in my back yard, about 4 meters by 3 meters. I was planning on buying just add water concrete mix, but how think should the walls be, and how much would the mix cost.

Also, how would i make a ceiling before i cover it in dirt, would cement be a bad idea?

Answer 1

even if you manage to form it so you can do all the walls in one pour and the ceiling so it doesnt collapse till it sets...you will need to pour it in one pour so you dont get any cold joints...you will need to use a rubber water stop between the floor and walls and the ceiling and walls...this is not a diy project unless you are a carpenter and finisher...been a finisher for 35 years and not sure i would try this one...

Answer 2

No offense meant, YES a bit of an odd question. Without knowing at all your intent, if the context of this BUNKER is as usually thought of, I suggest the issues are far greater than the substances used to craft one.

  PRE-MIX, most especially in bags seems an expensive, tedious way to proceed, and as far as the details of the Q, IE: Thickness, I suspect again, some issues more serious than just a root cellar, or place to hang out.

   The measurements approximate 14.6 ft  x 11 ft. a sizeable hang out, but hopefully not a life sustaining shelter for any time span.

Answer 3

Dude you need to hire someone or seriously research what you are trying to do. No one on here can see in your head to know exactly what you want to do. Get in touch with your local county inspector office and ask what the code is on the structure you are trying to build. As far as the ceilling, depends on how thick the slab is on top for the supports.

Answer 4

Buy about 9 burial vaults...cut out as needed, and bury the vaults...place a layer of corrugated galvanized steel over the top, and krazy glue the whole thing together.  It will take one weekend, about $1800 and you will be proud.   I have built about 14 of these and just have problems with the worms.  But I posted a question in the bug section for an answer.

Answer 5

Are you building a "slave hut" or something you actually plan to survive in should there be a nuclear holocaust?  Please think carefully, as if you are seriously looking for something to survive in, you need to do more planning that just some bags of insta mix concrete!  Covering anything with dirt after building should be inspected prior by local building officials and inspectors, which seems you may be trying to actively avoid, as if you weren't, a simple call to your local building officials would answer this question without posting it on Yahoo.  Please get some help and planning before building this death trap..

Answer 6

You clearly have no idea what you  are doing.  If you did, you would not be asking something like this.  You need to know how to construct forms and for something this size you would need to have a substantial load delivered by truck.