So Im building my bunker, you know (for when the russians attack!)

Its 8'x12', and about 4' of earth will be poured on top of it.

Anyone out there know how thick the concrete walls HAVE to be? 2in? 4"?

Just want the concrete for extra wall strength, and possibly to help keep out moisture. I know that concrete does allow moisture pass through, but I am assuming its better than earth on soil.

dude 2 inches or 4 inches, i tell u this i wont be going in there. why not bury a steel shipping container otherwise i would suggest at least a foot thick. im no engineer though i do drive an excavator for a living and all the basements i have dug have had walls a foot thick. that said they are usually pretty big buildings but the amount of dirt your talking about thats alot. im aussie so that is 10m2 dude. its about 1 1/2t per m2 so your looking at 15t of soil. Why do u want it so deep. why not put it just below ground level u will save on excavation costs and it will be alot safer easier to plumb. im actually planning on doing something similar when i get my own place but i will be building a shed over mine and covering the roof of the shed in solar panels to power my underground grow room. totally off the grid underground and concealed.

8' by 12' is less than the size of a snooker table. Its by no means big. I would say 4-8" will do... I would go for 8" for added radiation protection

burying anytihng underground just make sure you have a nice HVAC system

miosture will come right threw concrete. your going to need more space then that. your going to have to have a hole area for vents and fans. power ect. id go wth rooms 10x 6 id make at least 4 rooms. so your room should be 22 x 14 make block walls making that into four rooms one veg two flowering. and one control room. id cover the hole thing with rubber or pond linar roofing id also lay alot of pipe and gravel under it. your looking at alot of money. iv seen peopel buy junk buses trailors and bury them.

...so what is it? a tiny cubby hole or an underground building?

Well, it is obviously not for Nuclear protection!! .

Lol, and well the size of the room fits well into my budget. I have ordered a 8'x12'x8' building, of which I pay $100/m with only $100 down. Saves me the upfront cost. I can't make it a 22' as much as I would love to, mainly because of cost, but because it took me a long time to dig a 12'x12'x12' hole...by hand... lol... The original idea was to build a 12'x12' room, but the cost is high and I can't get ahead enough to purchase all the lumber, so financing will have to do. I figure as soon as I get some cash I can just pay it off. Will definitely be more cost effective I think. I figure I will divide it in half, then divide one half in half again. The 4'x12' section will be for flowering, I figure two 600w's will take care of that for now, moving to three asap, then 1000w asap. In one 4'x4' area I will set up for vegging, and curing. The last will be for storage, and monitoring station. All of my instruments, as well as a camera for outside. This is butted up against my place of business. Yes. I have a giant "swimming pool" outside one of my windows. Its a 20' drop! Lol. I figure I can always go bigger later, however the main focus is to get this bitch covered up! I live right next to an airport, so I have constant air traffic over my "POB", the local 5-0 uses FLIR pretty much nightly, so there is no indoor growing in my area. I would love to bury a shipping container.. but honestly.. how the hell do you do that? I could do it in a field where I could excavate the area, and just roll that thing into it...Lol. Other than that, mere magic will not do the trick!!

I will be dismantling the building I ordered and rebuilding it in the hole, improving its structure to bear the additional weight. I figure I will cover it in some sort of plastic sheeting or some tar before pouring the cement around it. Honestly have been thinking about skipping the concrete, and just leaving the wood as it is treated and would last a few summers at least. By that time I feel I will be able to afford a more proper shop. But I figure with the concrete it may last 10+ years, and I could just use it as my vault when I make the new area.

I would say remember, the concrete imo is more for degradation protection than strength. I will be reinforcing the building to withstand the pressure. Although I was unaware of the numbers. Really? 15 tons in a 8'x12'x4' area? I can't believe that. That would mean I moved over 50 tons of dirt total. Shouldn't I look like pop eye? haha No way. 2 or 3 dump trucks would fill the hole. Probably closer to 2. Of course I have no idea how much is in a dump truck.

stop just stop, if you were anywhere serious about this you sure as fuck would not be here talking about building a bunker with a few lights in it. WTF you want to keep cost down don't use your electricity to post crap like this. Dude load factors, rain snow, cars trucks WTF

You could drown in a hole like that

Ok Now I want you to go out in the woods and find the biggest stick you can carry and bring it back to me so I can hit you with it. DMF

Have a nice day and thanks for stopping in

Doesn't snow, and is in an area where there will never be anything that weighs more than a person on top of it. It is impossible.

And I am serious, which is why I am here. So why not offer something constructive?

Hurting my feelings, come on. =/

The bunker comment is a joke. Everyone else thought it was funny...

I know nothing of bearing capacity, load factors, etc, which is why I am asking. Shit. It is hard to even google things like that. I have no idea what to google. I looked into building basements for a while, but that really isn't the same thing. All I really need to know is actual weight of earth, or actual load on the roof, and best ways around it..

People used to build tunnels with little more than a few supports here and there, I highly doubt what I am talking about is sophisticated as you make it out to be. Its little more than building a two story house...Except with pressure from all sides. Lol.

well then put a concerete floor down first. then block up the walls y even us wood at all.. id us wood for form on the ceiling. but to pour concert on top its going to have to suport alot of weight even for 4 inchs. and if your worryied about ir. then y not make your vent go away from the bunker to say your dogs house or under a shed. or a smaller room for the air to mix in with fresh beofr going out. your going to need a 5x5 area for motors and venting eletrical things like that. basemnt grows suck let alone a bunker

Dude dump trucks usually hold 12t each.

And the reason for thick walls is because when it gets wet massive amounts of pressure build up behind those walls.

Huh, its funny,I was gona use shipping containers as a foundation/basement for my house to save money on concrete....used shipping container around $ 800

Biological Graffity said:

Huh, its funny,I was gona use shipping containers as a foundation/basement for my house to save money on concrete....used shipping container around $ 800

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Thats actually not a bad idea...as long as the containers are on a level footing that wont move...would be cheaper than pouring an entire foundation

You need to rethink your plan here because what you are planning on doing is crazy. You can not just dig a big hole and put a prefab building in it. I admire your ambition but what you describe doing above is just nuts. The fact that you would even think a 2" concrete wall might hold up, no mention of a footing for the walls, rebar, drainage issues, ect.......tells me that you have no idea what you are getting into. Not trying to flame here but what you are describing could end up killing you.

i like the idea about venting into the dog house

Alright. What each of you has done is read more and more into what I have said. I guess it is to be expected but I really didn't think I would need to lay out each detail.

I guess its fine really I will answer as it goes.

I had not intended on pouring concrete on top, just for the walls. I figure wood will buckle more easily than concrete. The reason for wood is a cheap, quick fix. This doesn't have to last long, just a year or so.

12tons eh? Well. I have moved way more dirt than I thought. Really doesn't look like that much... A big ass hole but not really that much dirt came out of it...

Do we have any way of calculating that pressure that will be exerted on the walls?
And because the weight is so much more than I originally thought, I can reduce the coverage to just a foot or so of earth on the roof.

It is impossible to grow indoors where this is, therefor the need for this project. The soil isn't really needed to protect against FLIR, however having a heated area of earth next to a POB would seem suspicious to me. I had intended on routing the air to the chimney, but I assumed that there would be residual heat left over from the walls. Not worried about smell at this location, there is no one around.

I like the idea of using the shipping containers as a foundation for a home. May use that some day.

Ok so, without drawing a diagram I will go into a little detail about how I pictured this coming together.

For the foundation of the room, I intend on using cinder blocks. I don't see how this would be a problem being that many houses are built on top of cinder blocks.
For the floor joist I will be using 2x6's that will be bolted onto 4x4 post on each side. This will be the same for the rafters. For an image each stud will be a 4x4 with a total of (4) 2x6's bolted to it. 2 at top, 2 at bottom.
The flooring will be typical 25 year plywood, and the siding is treated 25 year siding. I will be reinforcing the wall by having additional 4x4 studs in place. Instead of every 16" I will do every 12". I figure the weight pressing onto the left wall will transfer through the 2x6 joist and rafters to the right side, which will be supported by the weight pressing onto the right wall. To support the weight of the roof, I intend on having additional 4x4's connected to each rafter and joist directly in the middle of the room. For an image, there will be a total of (3) 4x4's bolted to (2) 2x'6s, spanning from left to middle to right. I haven't decided if having an arched roof would be better, a slant, have the roof come to a point, with the middle higher like most houses. (A pyramid shape). I figure having an angle of some sort will help displace water, and weight somewhat.

For the concrete walls, as I said I was thinking more to protect the wood from the elements, more than strength. I intend on covering the room in either tar, or some plastic sheeting.
For the walls however I intend on building a box for the walls however thick it needs to be, I had intended on running rebar, how else would the wall stand?

For drainage, I assumed having the pocket underneath the room would gather what little water there was, that would eventually soak into the earth. For plumbing I intend to install a water pump to pump used water out. I will be bringing fresh water in manually.

I worked and lived on a boat for years, where everything is compacted into tiny spaces, I am not worried about space. 8x12 will be plenty of room for me to do what ever I need to do.

Maybe I am so stupid that this doesn't seem complicated or a big deal... Why is everyone so no,no,no about it? Does anyone have any experience?

I appreciate everyone looking out for my health, that is why I am here because I treasure it.

Everyone said no,no,no to me about starting my business, but I did anyways and I made money. . .

A square foot of moist earth weighs approximately 100 pounds. If you had 4' feet of earth on top of an 8' x 12' building, that would be 38,000 pounds on a prefabbed structure. Then add in the concrete that you want to add, in addition to the 38,000 pounds. How do you think that your home would hold up if you tried to place 38,000 pounds on one 8' x 12' section of the roof?

TheRedBaron said:

A square foot of moist earth weighs approximately 100 pounds. If you had 4' feet of earth on top of an 8' x 12' building, that would be 38,000 pounds on a prefabbed structure. Then add in the concrete that you want to add, in addition to the 38,000 pounds. How do you think that your home would hold up if you tried to place 38,000 pounds on one 8' x 12' section of the roof?

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It'd crack in a heart beat!

Ok so one foot would put me at 9,600lbs. Should be able to take that right? No more than a few hundred lbs per sq ft.

Fucking sucks to dig your own grave. This has bad idea written all over it.

Something to also remember when putting a shipping container in the ground is that the roof on those are only made to hold weight on the corners and edges. Putting 2x6 boards accross it 12" of center with some 1 1/8" subfloor before loading dirt on top is a good idea.