Main things to do for underground rooms?

Hiya guys

Well basically I wish to dig out at least two storys worth of earth from my back garden, in order to build a fallout/blast shelter in the event of the Ruskis or anyone else, deciding to nuke the UK :O. I live in Birmingham (the second city and an obvious target asides London), United Kingdom. I plan to have upto 6 months supplies (food, water, toiletries etc) for upto 30 people, so it will have to be big and with pleanty of room for that many people.

The soil turns to clay after 1 or 2 meters I believe, have not dug down to see, but my old house which was less than 3 miles away, had clay when we dug our extension foundations. (I belive all soil in my city is the same, is that a correct assumption?).

Anyway, currently there is a garage on the spot where I wish to dig, I will demolish this and save as much of the current brickwork etc to use in the construction of the shelter. What are the main things I need to do when building?

Will I have to brace the earth, either side, to prevent the hole collapsing in on itself, under the weight of the surrounding earth? Also my neightbours garage is right next to my own (about 3 feet between them), will I need to be careful of possibly collapsing his garage when I dig down? If so how would I prevent this?

Will I have to get planning permission for building such an underground structure? Also is it possible there are utility lines, sewage lines etc in my back garden? How would I check to make sure the area, I intend to dig down at, is free of any underground man made obsticles?

I wish to build a blast shelter two storys down in the hole (it will be a massive hole as far as the room available is concerned , at least 10 foot wide by over 30 foot long for the first story dig down, then looking to build the blast shelter on the second story dig down, at least 6 foot by 6 foot minimum). under the blast shelter I wish to make a sceptic tank for all human waste, and as much as possible bio waste, from the fallout shelter (so I just realised it will be at least 3 storys deep lol, if need be I can dig down elsewhere on the floorplan for the first floor, to build the sceptic tank).

I will also be digging out for upto 5000 gallons worth of water storage, any tips on the water tank? I am currently going to buy 2-3 2200 gallon plastic tanks, then just bury them, with hand pumps attached to the pipes out of them. Is it better to build a concrete lined tank in the hole and just fill that?

Is it best to leave the bottom of the sceptic tank unlined (so the water etc can seep away in to the ground?) Also what sort of chemicals etc, will I need, to prevent it becoming dangerous to my health? (what amounts and how often should they be put into the tank?) Finally what is the best size for the tank based on upto 30 people using it daily? (got a big ass family and most my friends etc would be hold up with us in the event of a nuke blast, assuming we make it through the gridlock in time hehe, could turn out to be a massive waste of money, if we are stuck at work, school, shopping etc in the event of the nuke warning lol).

So once I get the hole I need to build in, firstly, what sort of foundations will I need to build, to support the blast shelter? (it will have no direct wall weight onto it from the fallout shelter) Then what sort of foundation will be suitable for the first floor blast shelter perimeter and garage walls? (it will also be holding the crossbeams, two or more layers of concrete brick ontop the beams and about 2-3 feet of earth ontop that and a concrete floor for the garage and the garage ontop, so will be quite a lot of weight needing supporting, not to mention a car or two ontop of that weight lol).

What type of brickwork, will be suitable for the fallout shelter construction? Should I encase the shelter with lead? Also should I encase the structure with reinforced concrete, poured onsite? What would be the best way to make a hatch for the shelter?

Will a regular wall covered in concrete on the outside, suffice for keeping out the damp and moisture of the surrounding earth on the first floor fallout shelter walls? Or will I need to waterproof it and add drainage around the perimeter? Also will it require insulation to prevent condensation etc?

I appologise if this is long and boring, but they are all question I feel need answering, before I consider this massive and costly project. I have budgeted around £10000 for this project, is that realistic? If it is considerably more than this, it will not be viable (I will be doing the whole project myself, so that cost is for materials only, no labour costs).

Also is it wise to have a socket ring and light ring, on seperate spurs, from the main board, in case power does not get disrupted? (they are already in place in the old garage, would just need to extend them down into the ground for fallout shelter).

Thank you for your time in helping me, please try to keep replies ontopic guys (I know how easy it is to start a whole new conversation hehe).

I am not a civil engineer, but I think I can help you with a few of these questions.

First, before you do anything at all. Check with your local city services to make sure that there are no pipes or lines of any type running under or near where you want to dig. I do not know how it works in the UK, but in the US, you do have to have the city approve of such underground construction, much like building a house. The last thing you want to do is hit a main line (sewer, water, gas, electric, phone, cable, etc).

As to the constuction, well, I am pretty sure there are plenty of manuals online with blueprints that you can download and modify to fit your available space. In fact, here is a google search just chock full of choices to review.

If you want to shore up against radiation, just make sure to include a metal such as lead in the build, since dirt alone will not fully shield out radiation seepage.

I just noticed that you said you were going to handle all of the labor. Do you know how to operate an earthmover, such as a backhoe or trencher (ditchwitch)? If not, factor in the cost of something like that for a days labor. Its not too terribly difficult to schedule one in advance, just compare prices based on the company, or individual.

You should most assuredly consult an engineer or building professional as to the soundness of your neighbors foundation in such close proximity. Just remember that is something bad does happen, his foundation is the first heavy thing that might be sliding in your direction.

As to the weight above you, plan on staging the support beams to disperse the weight. There should be a central column that runs from the lowest earthen point, to the shelter roof, supporting the exact center. From there, you can build around that. On the septic level, you only need enough support for the weight of the people and supplies. It also doesnt need to be a full 3 meter high full size room. Since this level will primarily be for waste disposal and refuse, it can be smaller, requiring less support material. I would suggest constructing a metal skeleton with poured concrete.
The main level now has a solid floor and a central column. On the corners, use metal beams that stretch from the ground floor to the roof of the main room. These will act as supports for both the septic and main levels. The use of these 5 support struts should offer solid support for the roof of the main level. Just ot be safe, add splines bisecting the corners radiating out from the central column. The roof of the main room is your greatest concern in the long run.
On the blast level, just make this puppy as solid as you can. Concrete walls lined with lead. It does not have to be large or spacious. It is there to absorb the impact and create a buffer for the main room. Nothing spectacular, just solid.

Access should be convenient, but safe in the long term. You should have two ways out from the shelter. A trap door inside your house somewhere that leads down a ladder to a sealable door to go straight into the main room would be one way. Opposite corner access through the blast level would be another possibility. A secondary escape tunnel could be build on the septic level. It only needs to be a convenient crawl space. At 25+ feet underground, it could be supported with timbers. Let this tunnel lead outside of your house, perhaps coming up right beside it. This will give you a better chance of being able to get out since your primary access will likely be buried under your house collapse. If you have a neighbor with a basement, perhaps you could link them.

That is about all I have. I would have to do a lot of research to develop an air and water storage/filtration system.

Finally, I think this project may run outside the amount you have allocated for it, so prepare to be flexible.

reply to post by Saf85


Well I’m hoping you aren’t planning on building a dungeon or making a place to “keep the bodies”.

I don’t know anything about building a two story underground bunker, however I feel the need to advise you to find someone who does near you, someone you may even need to pay to go out to your property and help you figure out what needs to be done. Just because someone on the internet tells you what they know it doesn’t mean they know exactly what they are talking about.




[edit on 6-10-2008 by rapinbatsisaltherage]

Thank you wheresthetruth and rapinbatsisaltherage for your helpfull comments, also thanks to the mod who moved this to the correct place in the forum .

Well I am guessing if I go well over double the project cost, I could just make a blast bunker as big as I can afford, and maybe half the live in time to 15 days. Fallout should lose enough radiation after 15 days, 30 days would give me a larger safety buffer, and also protect my family from rioting mad men looking for food, supplies etc lol. Most would be weakend or dead after 30 days of no food etc, leaving us to emerge into the world of "I am legend" .

There are a couple of other threads that pose similar questions. The current theory seems to involve using connex's for structure, either that or poured concrete. There is alot that goes into a sub terranian shelter, water, waste, storage, clean air. Not a small undertaking by any means.

I would seriously consider finding a professional engineer to work with you on such a project, otherwise you may be left with nothing but a caved in hole.

Also, 30 people is alot. A real lot. Just the waste alone generated by that many people presents a monumental problem. How much air do 30 people need a day? How do you keep things sanitary? I'm not saying it cant be done, enough time, money and smarts can accomplish anything, but I would certainly start to cull my "friend" list to cut this down from 30 to something more managable.

First of all good luck with your project. Its good to see a UK dude attempting something like this.

For size I think you have pretty much the standard issue semi detached back garden seen throughout Britain.
Doing some calculations I've surmised you've got 300 feet of 'space' but I don't know if you've factored in the offset you'll need cause of your neighbors garage and house etc.

My only hangup is that you haven't got the space to do something like this for 30 people.
Two storeys down and with 300 feet you have to start divvying up factors like the walls, flooring, essential furnishings and food supplies you'll be catcheing down there too don't forget. Then there's all your other goodies and equipment too, and all your other peoples stuff on top of that.
Even 15 would be pushing it.
I think no more than 12 people would be the max for a reasonable comfortable shelter.
But whatever your thoughts on this, go for it. Document it and post it on here so we can see a fallout shelter in the making

Cheers for the input people.

Well I supposes I could cull my friend list, but that would still leave around 20 immediate family members (including nephews and nieces etc), maybe it would be better to have two sites? One at my house and another at one of my older brothers houses? (I suppose I could try and convince them to part with the funds, they probly would just call me a paranoid, conspiratist lol).

I am guessing I will come up with a basic layout plan, take acurate measurments, then go see a engineer for more input and ideas. I really do not want to involve anyone from outside, given the nanny state the UK is, someone may think I am planning a terrorist attack and want a hideout etc. Really #ty place to live. I guess it could be easier to sell our houses and move to Australia or somewhere like that.

I will consult an engineer first, see what he thinks, what kinda price he thinks it will cost etc (I am sure I will blow a few hundred, just for ideas of the guy lol). If it still seems resonable (under £20000, building costs only, any contents, fittings & fixtures etc will be seperate from that budget, and like mentioned, as much work as possible, done by me or family).

I shall get back to here in a few days to see what he came up with. If it is ok I will begin by next week sometime (a benefit of no work and mortgage free living, plus savings ) and start posting pictures of the demolition and initial dig down.

A two story shelter seems wrong. I'm not an engineer (married to one though!) but it would seem smarter to have a one story with rounded walls to the ceiling. For load purposes.

Blast shelter, forget brick, use heavily reinforced concrete with a minimum of 8 inch walls. !2" would be better.

For concrete sealed in any space, you must have a dehumidifier. All the water within the concrete will be driven out in 30 to 60 days.

Your water storage, it's better to have a large tank within the shelter than being part of the shelter. If it leaks, you want to know. Tank goes in before the roof. May even want to consider 2 of them.

Big hole means a lot of dirt be put somewhere. Do you have this somewhere in mind. It will also be a larger amount of dirt than what came out. Ever notice that a hole dug and then refilled always has left over dirt. It's from compaction, so take "where to put the dirt" into consideration.

There are so many other things and stuff, it just is mind boggling.

You'll need ventilation, capable of being ran by human power if needed. Otherwise, you have just built a large confined space.

Good luck with your project...

reply to post by Saf85


Wow, youre not messing around. I like that. Ive seen a few on here who had great ideas, but never made the commitment (as far as I know) to move forward. Congrats on that.

Terrible thing to have such a large family, are you sure you really like them all that much? Just kidding. However, keep in mind, that while you may have a big heart and want to save everyone, sometimes it simply isnt feasible. No one ever wants to be put into a posistion where they need to determine who lives and who is on their own, but for the sake of the entire party, you may be confronted by this grim fact.

If you can only afford/ have space for 12 people, there will be some very difficult decisions down the road.

Even with that said, I commend you on your endevor, please keep us posted as to what the experts think as well as construction should it take place.

reply to post by Saf85


Good sir,

You will not be able to do this by yourself. Period....


Now, this is not to say you can't do a lot of it by yourself.

One immediate issue is logistics of digging such a deep hole. You are looking at 20' to 23' deep if not more for just the "main" pit. Not including the secondary holes for the water tanks. Like everyone has already stated. Speak to an engineer, have someone come out and do some preliminary digging. The preliminary dig work should tell you what kind of dirt you have etc... etc... and will determine a lot of things. Yes it has some upfront costs that do nothing for you initially. However it is better than finding out some enormous problem that can't be solved. Or can be solved but with double or triple the amount you have or want to spend.

You will need a small team of professionals to do the following.

- Assess the property
- Dig the hole, includes reinforcing the sides as they go down etc..
- Laying in the preliminary plumbing, also connecting it to the city mains. You may not want that, but I would recommend it. You can always have a cut off valve to separate your water from the city. In fact this is incredibly common anyways.
- Building the outside walls..(inside the hole) these walls can be either 12"+ block for the first 8-9ft. then 8"+ block the rest of the way, or it can be 12"+ solid concrete with plenty of re-bar every fourth block, "tied" and welded at the ends and corners. You WILL NOT be able to build the concrete walls by your self period. I may get flack from that statement. But trust me, if you have this many questions before you even start then you are not capable right now of doing that by yourself. Hell my father has been doing this for 30 years now. There is no way he could do this by himself.

The reason for the thicker bottom besides general support is the need to place I-bar a cross the bottom. In fact you will need to place I-bar a cross the top as well if you plan on parking cars on top. I like the aspect of a general support column in the middle of the structure. I would recommend making it large and hollow. So you can run electric wiring up and down it. Along with other plumbing, wiring etc.... Then your floors and exterior walls can be hole free and filled with sand, lead pellets, lead lining, or whatever your budget allows.

They will also have to lower down the tanks most likely utilizing the back hoe and chains. But that will have to be done early on.

You will also need someone to seal the structure. (at this point is is still just an over glorified hole in the ground with some walls around the edges. ) The sealing process will keep out ground water. Trust me go all out with that process. In fact I would double whatever the engineer recommends or at least ask him what is the absolute best thing you can do. Because in terms of longevity, it is the water damage that will get you. In case of leakage... you should also have two pumps. These pumps can run through the main center column to the lowest level. One being the main, and one the secondary.

Once other people have built the side walls etc... etc... done all the plumbing, electric... basically got the whole structure to a basic unfinished basement. THEN AND ONLY THEN should you start doing the rest by yourself. Building in the kitchen, bathrooms, bedrooms, storage areas, putting up lights. The norm... The finishing process alone will most likely take at a minimum if you go really cheap, around $26,000. Not counting the cost of your labor and time. There are so many things I could recommend but that is up to you at that point. Please for the love of god and all that is holy don't attempt the main structure without professional help.

The "unfinished portion" will probably cost you around $20,000+. If you are going to do this. DO IT RIGHT!!




-

Some very well intentioned advice but unfortunately some of it is just incorrect or based on outdated concepts. I've studied this myself and I think I can help you somewhat.

Let's start with misconceptions:
1. You need to be deep underground
- For "blast" protection this is true, but in all honesty if you need protection from a near direct hit you simply won't be able to build a shelter capable of surviving yourself. If you're within the blast radius of a known target you should look into a pre-built shelter.

The bad news is they are very expensive. The good news is they are very, very nice with battery power enough for 6 / 12 / 32 / 64 / 128 people depending on which unit you can buy. They also have water, waste disposal, radio / tv masts, tamper proof hatches with gas and projectile defense, tamper proof and biological / radiological proof air supply, etc, etc.

Here they are - the "Radius" fallout shelter
You should take note of just how large the 25 person "condo" shelter is. It's really, really big.

The truth is as long as you are outside the blast radius you simply need fallout protection. This can be accomplished using a variety of improvised means, most of which consist of putting enough dirt in between you and the radiation. 6 feet of earth is enough for the worst possible radiation load, this doesn't factor in blast proofing, however. The owner of the Radius shelter co authors the definitive book on nuclear fallout and blast shelters, you can find information on the book on their website.

Building a direct hit blast shelter or one within a certain blast radius will be difficult as you have overpressure to deal with. The human limit is around 20 psi - this means you need any air vents, exhausts, etc to be big enough to supply your population but small enough to prevent the overpressure wave from equalizing in the shelter. This usually means using just enough total ventilation volume and splitting it among several small pipes rather than one large one. The commercial shelters add a baffling system to prevent this as well as keep possible intruders from suffocating you, drowning you or smoking you out.

2. You need a lead lined shelter
See end of number 1. In addition, modern nuclear weapons are "different". They create an intense radiological energy on ignition and leave behind a type of fall out which disperses faster. While the traditional precautions will still be a good idea the worst of it will be manageable with safe habits after 2-3 weeks to 30 days or so, (depending on distance from ground zero). There is a radius within ground zero which will be uninhabitable due to penetration.

3. You need concrete and lots of it
This depends on how deep underground you go. There is a type of underground construction which is cheaper than you might think. I bought the book "The 50 dollar and up underground house book" The author has a variety of plans which make use of his own devised and long tested methods. They make for very inexpensive and fast construction which solves the typical humidity issues. He's designing permanent houses for living which include an area in them to serve as a bomb shelter. The techniques could be easily adapted to build a cheaper and more livable shelter.

I actually plan to buy a huge parcel of land in the country and build a residence using these techniques as well as others. His designs usually include underground greenhouses, a huge bonus in a post nuclear home.

Now that all said, the deeper "underground" you go as opposed to alternatives involving building into a natural or artificial hillside bring the problem of soil pressure. If you notice, most govt and commercial shelters are built extremely strong, not just for direct hit survival but so they can withstand the enormous pressure of the soil around them.

You have a variety of options.
You could build partially above ground by creating an artificial "hill" of rocks and soil, even concrete and support beams, etc. Your main concern would be having enough space for your plans. If you decide to go "deep" you're going to need some consultants to avoid collapsing your neighbors property or damaging the foundation of your own house.

My first recommendation would be to buy a radius shelter with installation if you can afford it.

The next would be to look into "hacking" your own radius shelter by using a pre-built structure of some sort you can adapt. Following the design and concept of a radius shelter would serve you well, as would looking into some of the modern architects who design extremely small living spaces. (Treehugger actually has links to a number of these, a google search for architect+small+houses or efficient+living+spaces should help you design a living space for 30 people using as small of a shelter as possible.

Another good reference is a civil defense site with plans and data on building shelters, it was updated in 2005 last I can see: radshelters

(Those key chain Geiger counters are pretty nice, though you can build your own if you have electronics ability).

Good luck, if you go forward be sure to update us with pics and details. If I manage to build mine before TSHTF I'll do the same.



[edit on 13-10-2008 by nfotech]

[edit on 13-10-2008 by nfotech]

The main problem you want to avoid is undermining your property and getting settlement in your house. I doubt your home Insurance would cover you if you screwed it cos of this!

Anyway, as an environmental and geotechnical engineer Clay's a good start. Ideally you should get a couple of boreholes sunk in your garden 1) for impact / penetration tests to soo what loading the clay can support and 2) so you know what level groundwater lies at.

As for utilities you can order them from companies like suziphone which will charge around £300 for the full set, or you could approach each utility company directly (under a fake company name) and ask for each set, which you'll prob get free of cost.
However, If you hit a gas mains etc expect to get fined senseless (companies usually have insurance for this!)

You'll def need to get the walls and roof's shored up because the last thing you need is for it to collapse one you!

Without knowing the exact area a non permeable gas membrane in the floors and walls may be needed to stop methane and or carbon dioxide gas migrating from any buried / made ground in the area. You will also need ventillation.

I admire your fortitude, however what you plan just isn't doable. For that many people you will need much more space. Sewage will be a major problem especially with clay as a base.

Water table issues must be watched closely, going down is not the best option.

Earth sheltered is a better option. See the above mentioned "$50 And Up Underground House Book" Great in most respects especially do it yourself.

Ventilation is a must. Materials for what you are wanting to do will cost much more than what you have budgeted. Here in the US concrete will cost upwards of $75-80 a yard. Rebar is very expensive and you will need a lot. Don"t bother tying into the electric grid. No one will have power if TSHTF.

Now consider storing solar power, who goes out to set it up? So that leave you with a generator. Storing fuel for thirty people for thirty days is tough. Not to mention keeping it stable and the octain rating up.

Doing all of this in an urban setting and getting permits will be impossible. They just will not let you do any type of non-standard construction.

Your best bet will be to move to a more rural setting and building earth sheltered and using passive solar for heat and electric. Minimized consumption with led lights and ultra high efficency appliances. Maybe a composting type of toilet, but for such a large group of people you will need a few.

To do it on the cheap and do it quickly, modified shipping containers can be used an earth sheltered and covered. All plumbing and electric can be run before burial. Plus this can be done by yourself with little help. How are your skills at these tasks? The last thing you want are backed up toilets for thirty people in an underground shelter and no way to leave.

respectfully

reluctantpawn

Dude you would need major planning permission and well qualified builders/surveyors to pull this off.

I dont know your exact intentions but this is a LOT of labour, how much cash do you have to spend on this?

If you look around the Radius bomb shelter site I linked you can get some great ideas for a do it yourself system. If I had the money I'd buy the 5 person shelter form them, it includes carbon Dioxide packed food and even the fuel for the slow turn diesel genset. I think the lowest price is around 70k, however.

As for the ideas...

They use a separate, preformed structure which is buried for the powerplant. The electrical connections feed to the battery sets which are contained in the shelter. That solves the ventilation and fire hazard issues - though I'm sure the batteries require some amount of ventilation as they vent explosive gasses. (Unless they're huge Lipos which I doubt, that would be an even bigger fire hazard).

The water tank is also a separate, buried stricture and they use a sewage system based on your avg trailer park septic system. It leeches into the ground which filters the water naturally and returns it to nature. Most septic systems make use of bio safe chemicals to break down solid waste and neutralize odors. On occasion septic tanks have to be pumped out due to overloading or use of paper products not made to break down fast enough.

The old way of building shelters, some meant to last for years was far more difficult. Building a system for 30 days minimum, 60 to be safe is more practical.

The ark project used schoolbus bodies, reinforced and encased in concrete. Of course, they have horrible humidity issues. They could have used dirt in place of the concrete and lined the pit with PSP, ( a type of plastic you can buy in large rolls for next to nothing).

If you're serious about a 30 person shelter I'd find a preformed structure to use like a bunch of large steel tanks from salvage tanker trucks or ship containers. Have them cut to add in a doorway or two and bury two or more of them side by side, connected and fairly deep with another shelter structure on top of them halfway above ground with at least 6 feet of soil on each side and on top. I think you would need a minimum of 6 shipping containers and it would still be very tight quarters. Add another container off to the side to contain the genset and water tanks, food storage, batteries and electronics with a fire door between it and the shelter.

Design the living space to be hyper efficient, use shift sleeping to cut the beds down to 10, stock up on Xanax and lots of herbal tea to keep people relaxed.....

I prefer the full time house with shelter as I don't think we'll get much warning, especially in a pandemic or bio situation. That's another good reason to live as far out in the country as you can practically manage.

Let us know how things are shaping up...

Hiya guys

Just wish to thank everyone for the input and suggestions. I have been pretty busy with the birth of my second child so have not had much time to look at this plan.

I did speak to an engineer and he did mention, to build anything I was asking in the initial post, it would be well over the budget I was thinking along the lines off. He reckoned it would be around the £50-60k mark! Not to mention it would be very difficult (since he did not draw up any plans etc, he did not ask for any cash for his time, plus I kinda buttered him up saying I would have him draw up the plans for anything I did do). He did recommend, that I just stick to a fallout type structure to keep within my budget.

I really do not fancy rural living, with the idea of the urban fallout shelter looking kinda shattered. I think it best I just live in the UK for a few more years, then ship off with my family to a country that would be more safe in the case of nukes being sent toward it.

Moscow seems a nice place, plue the s-300/400 and in development s-500, along with the multitude of missile shields in place, makes it as safe a place to be when the # hits the fan, then again somewhere like Dubai seems to be appealing to me, plus Dubai posses no real military/industrial threat, so would be likely spared from any fiery fate. Also it is a very nice place to live, great weather, all the local amenities you can ask for, the fuel is dirt cheap and pleanty of business oportunities to invest in.

There is a huge problem that I don't think anyone pointed out. Since you said the substrate was clay, be aware that you had better have a good French Drain system, with a sump pump inside your basement, and a second or even third pump as backup. Otherwise, you risk having your entire underground structure implode. It happens all the time to people during heavy rainy periods, if they don not relieve the hydrostatic pressure on their basements. I had a friend who had that happen to them, the entire basement imploded, and then the house collapsed into the remaining hole. It was considered an act of God, and was not covered by their insurance. It bankrupted them. they did not have the French Drain system around the foundation.
DO NOT ATTEMPT a basement in your area without it.