Fallout shelter design

[norincofl]

Hello,

I'm currently requesting quotes on a 10x20 fallout shelter design and installation from some out-of-state builders as well as somewhat local metal fabrication companies.

We're looking at both a steel framed unit out of plate steel and comparing that against shelters designed using 10' culverts. 36" of earth on top of shelter with a ladder entrance making a 90 degree turn into the shelter space with two air vents able to be closed from the inside.

Some of the advantages I see in using the culvert as that it seems less expensive to build as well as giving you significant storage space under the floor. The steel framed unit gives slightly more floor space.

For those of you with an existing shelter, what would you have done differently with your design or installation the next time around?

[1Admin]

10 foot plus 3 foot of earth for a PF of 1,000 is a LOT of ground.

In many areas of the southeast that would mean mounding.

PLAN for water infiltration and have an ironclad way to get rid of it, I don't care how your shelter is built, who builds it or where it's installed- PLAN for it.

Mold WILL be a problem after any serious water infiltration. You can try to remedy all you want but what it will really take at that point is trashing everything inside and starting over.

MAKE SURE you get and use the rubber gaskets that are available for connecting pieces of smaller (2-4') culvert. You will NOT have an adequate water seal without it.

[rockriver]

some associates are considering the same thing.
if they go with culvert, they are thinking of coating outside with drylok or foundation sealer.
along with ?French drains ? along sides of exterior with all sitting on top of about 12" of 5-7 or larger gravel.
--
let us know as planning/building develops.

[cpt_sfc]

You don't have to go with round culvert as they have a tri - angle type out that is wide at the bottom and rounded on top. Our local linex guy has been doing under ground homes and root cellars after install to allow complete coverage/seal of top and sides. Kinda pricey but will last a life time . Also you can have roofing spray foam applied as it is covered from the sun. Drainage depends on your water table and earth properties , But a couple ft of 3/4 run washed stone and a layer of pea gravel will allow water to go to a dry well at each end of shelter. A shelter on the flat surface can also work quite well , but the mound will be visible from the surface. A right angle entrance is easier to do on top of ground and mass affects rad count so the more earth on top and sides help. Air transfer will help with moisture but all air needs to be filtered of particles from the air out side. Drains to sump hole can also help your French drain but I would use 6" perf pipe with it. Look up army ammo bunkers and it will give you a good idea on how the front and back are held in place and how it all ties in. Have a blast plate in both intake and out flow pipes , that you can access from inside. Furnace filters put in sequence can make a filter for next to nil. Make sure you have extras to replace as needed. a solar powered fan can keep air fresh when shelter just sits, EMP is still ? about how it effects solar and batts . A manual fan needs to be able to be placed also. There is a lot to read up on before you leap into it. Just remember you wont have to live in it for years as rads will decrease fast depending on where you are located. Goo d luck and you can save money if you research it and act as your own job site boss. Even distance from fallout help greatly so if you were to put a pole barn over it the space would mitigate the rad exposure.

[norincofl]

I've had my first and second meetings with the local metal fabrication company. They advertised "storm shelters" and custom work so I presented them my plan, talked about the designs, gave them the options I was looking at and they agreed to come up with some quotes.

At our second meeting them basically came back and said that due to their research and the existing site considerations they didn't think they could do it. The water table was too high and even with added concrete as ballast to prevent floating they didn't feel like they could adequately coat the steel to prevent rust and water intrusion for a period of time that they felt comfortable with.

So they didn't even give me a quote for labor and materials. Which I felt was honorable of them.

Back to the drawing board!

[Rmplstlskn]

The only "bunker" I ever saw in low-land Florida was on Peanut Island near West Palm Beach. But it was gov't money that built it, so they made it work. Can't imagine the $$$ it would cost in a place with a high water table.

Rmpl

[Lowdown3]

You could go down to an 8' tube and partially bury it and then mound over it.

They WILL pop out of the ground if not adequately covered.

[cpt_sfc]

Don't give up on the idea. Go above ground. Think out of the box. Use footings with a floating slab laid out on pea gravel and foam board if in winter area. Use culvert (large flanged type ) bolted to footing Use 3/4 bolts sunk deep into footing to assm. Concrete back and front wall. Retaining wall around bld to hold all the ballast/dirt what ever. Any dense filler will work . Outer wall 4-6 ft from bld will allow a smaller foot print. Some folks even lay to walls 3-4 ft space between walls and fill it. You can always plant on the top and slope sides. http://www.il.ngb.army.mil/MilitaryA...erview2016.pdf Look this over inside is a pic of a above ground ammo storage bld . No reason it would not work if entrance was set bak into front. I don, know if it transfer over but it will give you an idea.

[cpt_sfc]

Further- if you look down to where it says(Live Fire Breach range) a small pic will show you what I mean. Entrance could be a double wall in front with off set door and 90 deg turn and a hallway to the other door. The size your talking about would be well under 10 grand here in this area. The culvert is a half circle with bolt pattern that you would set on a high footing and bolt in place. I have a tire store in my area made out of a span of culvert 36 feet across on top of 4 ft. walls, of course no dirt cover , It has been there for 30 plus years.

[cpt_sfc]

http://www.popularmechanics.com/tech...a4600/4325649/ Another article from pop sci.

[norincofl]

Small update: I have reconsidered my area and the water table issues and we've decided to go aboveground, in the interior of our home. I'll be building using CMU's and installing inside a large utility room. I've got an appointment soon with a engineering firm to reinforce the slab prior to stacking blocks.

[Lowdown3]

To start off, what's the approximate distance to the closest target?

Concrete blocks, filled with rebar in each cell and filled with grout mix gives you about 8 inches of concrete. I know it will stop .308 at close range cause that was the highest caliber I had to test my house.

IDEALLY you would have had bar running from the footers all way up to tie into the rebar in the cells of the reinforced block.

A lot of places built "safe" rooms like this above ground in houses, that would be the words I would use with any contractors, etc. Obviously you'll have to modify any "safe room" plans a bit however.

[norincofl]

To start off, what's the approximate distance to the closest target?

Concrete blocks, filled with rebar in each cell and filled with grout mix gives you about 8 inches of concrete. I know it will stop .308 at close range cause that was the highest caliber I had to test my house.

IDEALLY you would have had bar running from the footers all way up to tie into the rebar in the cells of the reinforced block.

A lot of places built "safe" rooms like this above ground in houses, that would be the words I would use with any contractors, etc. Obviously you'll have to modify any "safe room" plans a bit however.

"Hi, I'd like to build a fallout shelter in my home" was replaced with "Hello, I'd like some engineering done to help me build a safe room."

25 miles or so to a former nuclear plant, still in the decommissioning process. I am using Joel Skousen's High-Security Shelter book as the inspiration for the current plans. It advises using 12x8x16 CMU's for building aboveground which only gives a PF of 32. We're going to pour a 12" ceiling to right below the ceiling joist and then fill the spaces between the joists with 8x8x16 filled block. After the ceiling and walls are built I will go back and add another 8x8x16 wall and the footings are being engineered to support that load as well. And that's about the best I can fit inside. It'll bring the PF close to 1000 with the second wall and ceiling improvements which is an significant upgrade to the Skouson plan.

[cpt_sfc]

Don't forget the roof line as it will increase the protection level as well as distance of out side walls from room. Good luck and pray non of us ever need one.

[Lowdown3]

Don't forget the roof line as it will increase the protection level as well as distance of out side walls from room. Good luck and pray non of us ever need one.

+1

Distance.

When I lived in Florida it was in a 2 story house. My best nuke plan was to get into a closet under a staircase that I kept all my bulk grains in. Basically burrow into the stacks and use them as a bit of shielding. With the distance to the roof giving a little bit of protection also. Thankfully never had to try it....