Outside Concrete Shelter

[RedJohn]

PDF from FEMA

This family fallout shelter, designed primarily for homes without basements, is a permanent home shelter to be placed in the yard. It is designed to have a protection factor of at least 40, which is the minimum standard of protection for public shelters throughout the United States. This assures that persons inside the shelter will be protected against radioactive fallout following a nuclear attack, and will also have some protection against blast and fire effect of nuclear explosions.

Following are detail drawings of the shelter, which is capable of housing six adults. It can be built of poured reinforced concrete, precast concrete slabs, or a combination of concrete blocks and poured concrete. If it is built as detailed with the top near ground level, the roof slab can be used as an outdoor patio. The shelter is accessible by a hatch-door and wood stairway. Fresh air is provided by a hand-operated centrifugal blower and two ventilating pipes that extend above ground level. In areas where there is poor drainage or where the ground water table is close to the surface, the fourth modification on page 5 should be used.

Before starting to build the shelter, make certain that the plan conforms to the local building code. Obtain a building permit if required. If the shelter is to be built by a local contractor, engage a reliable firm that will do the work properly and offer protection from any liability or other claims arising from its construction.

[hedgehog]

I was just looking this. With all the wicked weather in my neck of the woods the wife started talking about tornado shelters. Since I was going to have a large patio installed, and have no basement, i thought why not add some more concrete and create a multi use shelter. Any Ideas on this subject.

[RedJohn]

What multi-uses are you talking about?

[hedgehog]

Well a place for prep storage for one. I'm not very far from Joplin. That storm that hit them hit my area also. Had rotation close enough for us to empty out the very very small closet in the kids bedroom. It's one of the two only rooms with out exterior walls. Both being tiny closets. It got me thinking how screwd we are in our home. Most homes in my area do not have basements. No protection for family or our preps. I have zero storage space. I do have a large garage but our stuff is to visable. (even after trying to contain it). God forbid a storm or worse happens it can all be blown away in an instant.
I am getting close to building a large patio between the house and the pool so I was thinking and underground shelter with steps. entry from inside garage, convient for storage, convient for sheltering through the worst. Best part it was not my idea. My wife has been gun safe shopping, and the size we would like is expensive. She sugested an above ground shelter that can be used as a vault also. I figure for a few grand more I can solve a visable food storage issue, visable ammo issue, shelter issue and patio issue. But how far to take it is the issue. I would want easy entry, well lit, maybe even with a small ac/heat chico unit. Secure with one of those bullet proof coded locks. Seperate escape tunnel etc. Ideas? *sorry for spelling errors, cant get iespell to download.*

[bacpacker]

Your plan is sound IMO. In particular since it was the wife's idea. I tend to run with them when she hits a good one, gets me some points for doing my ideas :)
In your neck of the woods a well built shelter could well be a life saver. All the other uses just icing on the cake.
Something to look into, around this area there is a company that make septic tanks and they advertise pre made concrete storm shelters. Not sure of their sizes, but might be worth reasearching.

[RedJohn]

Concrete requires equipment that you may not have. You could do it in bricks.

[hedgehog]

Well i have to have a patio poured anyway. It will be raised because my back yard is sloped. I was considering blocks, but my brick/block laying skills are lacking. My front mail box, which my buddy and I pit in, has a kind of cat in the hat swagger to it so i better get a pro. I'm looking up the ventilation aspects simple to start but upgradeable so I can have it filtered after I save up some cash. Has anyone tried this yet? I would also like my gen. incorporated into this also. Outside installation, bolted to patio. My biggest problem is how loud it is. Has anyone added mufflers to theirs?

[bacpacker]

In your case I wouldn't be real concerned about OpSec. There have been so many tonados around this year, someone putting in a "tornado shelter" would raise much attention, with a patio. Should you choose to go with block, I would suggest all that are below grade be poured with rebar for strength. That's they way they did my basement and we have had zero issues even from cracking in the motar joints. On the inside, we painted the block with Damtite. It a poweder you mix with water till you get the right consistancy then put it on the blocks. 2 layers and it will keep water from seeping thru. Outside we did a french drain at the base, then 2 layers or tar and plastic before we backfilled. We never had a issue with water coming in. Our house is on a bit of a slope as well.
No expereince with fitlering or gen's.

[hedgehog]

Backpacker, was the tar and plaster on the wall? Any condensation issues? Great info. Your right about the op sec. I'm sure I'm not the only one with hind sight lately, even if I have other motives. I'm going to start some rough sketches with a list of building requirements. When they are ready i'll try and post them for some feedback. I hate "building remorse". Put a large garage on the house a few years ago and the wife said "why don't you put a room above it?" I said "this garage is huge!, not need." AAANNND I'm out of space. All about advice now.

[RedJohn]

There is a trick that I can't remember about the humidity due to outside condensation in the ground. I'll try to find it for you.

[bacpacker]

We've not really had condesation issues. Our basement is underground on the north side, south and west are above grade, and the east side is about half on a slope about half and half. We do have very high humidity here, so we still try to keep all mositure related issues at bay, but we've mever found mold or mildew anywhere in the basement.

The tar and plastic was applied to the outside before backfilling, The plaster mix was applied to the inside as soon as the block was laid up and motar dry.

I know what you mean about building remorse. We found plans in a magazine and once we bought them, we set down with our contractor and made some changes to them. In hindsite 17 years later, there are several things we would have done differently. some minor things we would have liked, others would have made a positive effect. Alot of it was due to being first time at building and not knowing what to do. Advace planning will help and huge amount.

[LUNCHBOX]

Well i have to have a patio poured anyway. It will be raised because my back yard is sloped. I was considering blocks, but my brick/block laying skills are lacking. My front mail box, which my buddy and I pit in, has a kind of cat in the hat swagger to it so i better get a pro. I'm looking up the ventilation aspects simple to start but upgradeable so I can have it filtered after I save up some cash. Has anyone tried this yet? I would also like my gen. incorporated into this also. Outside installation, bolted to patio. My biggest problem is how loud it is. Has anyone added mufflers to theirs?

I didn't need this but my cousins noy used a styrafoam box for the noise. Just duct taped the hell out of it and set it over it. (be careful of the heat coming from the exhaust, he used a small bathroom vent near the tailpipe) I heard it and it was a big difference.

[2600i]

how about a cement/brick picnic table to hide the stairs into the shelter instead of it being off to the side of the patio. also you could put in some observation slits toward the top and protected by the over hang of the table top. hinge the table top with a quick acting lever like on navy ships to secure the door.

[dragon5126]

Since he has a garage in place Whats the possibility of putting a "garden shed" at the back of the garage over the entrance, and putting a door in the garage into the shed, Assuming an attached garage this would prevent the need to go outside should/when (Missouri is in Tornado Alley) the need of shelter arises. Since this is being built as a "shelter" permits should allow this, however if you do go this route consider a secondary exit, not necessarily as elaborate, perhaps just a hatch just above ground level sufficent to prevent water ingress and a rung type ladder rather than stairs.

[bobthe]

Since he has a garage in place Whats the possibility of putting a "garden shed" at the back of the garage over the entrance, and putting a door in the garage into the shed, Assuming an attached garage this would prevent the need to go outside should/when (Missouri is in Tornado Alley) the need of shelter arises. Since this is being built as a "shelter" permits should allow this, however if you do go this route consider a secondary exit, not necessarily as elaborate, perhaps just a hatch just above ground level sufficent to prevent water ingress and a rung type ladder rather than stairs.

this is typically frowned upon because if a tornado comes through and turns your garage into a pile of rubble then you could be trapped an unable to opent he door. thats why most shelters are typically located a little ways away from structures. you can plan for this by having a large hydraulic ram to force the door open even if a great weight is on top of it, but obviously thats the least desireable situation to be in, shy of NOT having shelter.

[The Stig]

this is typically frowned upon because if a tornado comes through and turns your garage into a pile of rubble then you could be trapped an unable to opent he door. thats why most shelters are typically located a little ways away from structures. you can plan for this by having a large hydraulic ram to force the door open even if a great weight is on top of it, but obviously thats the least desireable situation to be in, shy of NOT having shelter.

Have to agree with bob on that one. I'd be wary of having any structure that could prevent my egress. Even worse would be if some freak turn of events caused the shed to collapse and prevented you from getting in the shelter in the first place. As dragon pointed out a secondary entrance/exit would be mandatory in you go the "hide it in the shed" approach.

But even with a secondary exit (along with it's associated complexity and cost) if it's large wooden type shed and somehow catches on fire, directly above the entrance to your hidy-hole that strikes me as a bad situation. It probably isn't going to burn that long to create oxygen problems, but it isn't going to be a good situation.

[Jerry D Young]

The above ground double wall shelter in MP-15 might work for those areas where ground water is a problem, or for those that just don't want an underground shelter.

It can be enlarged by using inside columns and a beam to make it wider and longer. I'd also make the fill thicker as well as the roof.

Just a thought.

http://standeyo.com/News_Files/NBC/nuke.shelters/MP-15.fam.1959.pdf

[realist]

Hedgehog you need to check the ground water situation. Make sure that you plan for water problems, sumps will help with this. Also if you want to do this by yourself take a look at blue walls which are a concrete form that is made from foam that go together like blocks and then you pour the concrete. They look good but I do not know about the costs. If you are going to put in block and have not done it before I am going to be using Blue Max Liquid rubber, take a look at their website it is interesting. Ames' Blue Max Liquid Rubber (http://www.amesresearch.com/bluemax.htm) One thing about block I was told do not go more than six high then let it dry then six more, this will prevent blow outs. Do not forget to put in bonding beams with the block. Also they make some drains that go against the wall to channel off the water if you have drainage. I understand that Op Sec is important however when you are doing things in concrete and you can get in a cement truck it is a plus. I would think that for those of you in tornado country a shelter would be the norm so that putting in a hardened one would not draw the attention that it would in my location.

[dragon5126]

Thats the southern ideology, the reality that has been proven in the north is that when a structure does come down they dont come down in a huge pile. If the storm were to blow towards the secondary exit the structure would clear the primary and vice versa, which is why it would be located off a garage which is only a shell rather than a primary structure like a house Believe me, we dont have people trapped in their basements when tornados hit, and we get hit just as often as the south does, just not always in the same locations.

[dragon5126]

Have to agree with bob on that one. I'd be wary of having any structure that could prevent my egress. Even worse would be if some freak turn of events caused the shed to collapse and prevented you from getting in the shelter in the first place. As dragon pointed out a secondary entrance/exit would be mandatory in you go the "hide it in the shed" approach.

But even with a secondary exit (along with it's associated complexity and cost) if it's large wooden type shed and somehow catches on fire, directly above the entrance to your hidy-hole that strikes me as a bad situation. It probably isn't going to burn that long to create oxygen problems, but it isn't going to be a good situation.
A large shed would not be conducive to the idea of concealing the entrance, and any underground structure should always have a secondary exit no matter what it is. Basements must be built with at least one openable window away from the primary entrance to meet code in all states for this reason. it is a matter of seconary exit as well as viable airflow. Obviously the shed would be metal, not plastic or wood, as neither of these two items have the longevity or safety factors of metal, In fact up here it isnt even legal to place a shed that is combustable against another building, as they are too often used to store fuel for lawn mowers and similar and are required to follow the rules set for dwellings as far as distance to another building, whereas metal utility sheds are almost universally exempt.

[dragon5126]

Hedgehog you need to check the ground water situation. Make sure that you plan for water problems, sumps will help with this. Also if you want to do this by yourself take a look at blue walls which are a concrete form that is made from foam that go together like blocks and then you pour the concrete. They look good but I do not know about the costs. If you are going to put in block and have not done it before I am going to be using Blue Max Liquid rubber, take a look at their website it is interesting. Ames' Blue Max Liquid Rubber (http://www.amesresearch.com/bluemax.htm) One thing about block I was told do not go more than six high then let it dry then six more, this will prevent blow outs. Do not forget to put in bonding beams with the block. Also they make some drains that go against the wall to channel off the water if you have drainage. I understand that Op Sec is important however when you are doing things in concrete and you can get in a cement truck it is a plus. I would think that for those of you in tornado country a shelter would be the norm so that putting in a hardened one would not draw the attention that it would in my location.

Cant find the links right now, but there several companies that sell modular poly structures that would fit his bill. They look similar to oversized septic tanks with various fittings for what amounts to human sized "habit trail" set ups like they sell for hamsters and gerbils. Not the greatest for radiation protection unless it's buried deep enough or concrete is used but theey are made out of the same stuff as plastic 55gallon barrels.

[bacpacker]

There is a septic tank manufacturing co around here that has started selling prefab storm shelters. I haven't took a look at them yet, so Ihave no idea about the size, cost, or anything else. I'll try and get some info on them and throw it up on here.

[dragon5126]

If they are made the same as the ones I have seen and are of similar size they are almost a no brainer for a storm shelter. Up north here they aren't too popular because everyone has basements. If my yard was larger though, I'd find an excuse to stick a system in the ground and plumb entrances into the basement and the garage as well as an outdoor hatch hidden in the hedges...

[bacpacker]

We have a basement as well and the land lays so that I think one of these would fit that bill quite nicely.

[Sniper-T]

How about starting above ground, then burying it? within a short time frame, it could be relandscaped in short order to look like a natural mound.

Start with something like this: Tents that turn into concrete in less than 24 hours. [VIDEO] (http://www.wimp.com/concretetents/)

[Stg1swret]

Do a search for ICFs ( Insulated Concrete Forms) they are easy to work with and can be used above and below grade. You can design any shape building you want, and would work great for that "shed" entrance to an underground shelter.

[Sniper-T]

Some friends and I have discussed the concrete tent idea at some depth and I had planned on doing some experimentation this summer, but time just didn't work out. what do you guys think:

Proposal: see if regular tents, either nylon or canvas would work in this same manner.

Methodology: set up test tents in appropriate places around my property, then use a spray bottle with a cement/water mixture to spray the tent, just enough to wet it, then allow the concrete to set. repeat.

Variant: Assuming the first few coats work, add a strength membrane, such as geotextile, for subsequent coats


Concern: the concrete would react with the nylon and disolve it
Solution: switch to canvas, use a fast cure cement, coat the nylon prior to spraying

Concern: The immediate weight would collapse the tent in whole or in part
Solution: reinforce poles, ties, etc.

Concern: The zippers/flaps would be rendered useless, impede access/egress
Solution: apply petroleum Jelly to the zipper until enough coats are built up to retain rigidity. replace zipper with usable door/window system

Concern: Design usable door/window system.
Solution: hatches? create solid structure and cut concrete afterwards

???

Thoughts??

[ravensgrove]

This is fascinating. I need to build an above ground root cellar, our water table is too high for a below ground one. We cloche everythign in straw now, but I need a long term solution. This sounds promising.

[ravensgrove]

Well scratch that, holy heck the big concrete canvas one is $28,000 and the smaller size is 22,000. That's not happening....back to earth bags.

[helomech]

Well scratch that, holy heck the big concrete canvas one is $28,000 and the smaller size is 22,000. That's not happening....back to earth bags.

If it lasted more than 10 years I would order one of them.

[Sniper-T]

Hense... our thoughts of making our own.