how to do a suspended concrete ceiling? (bunker build)

15 May 2013
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United Kingdom
Hi all,
I want to at some point build a bunker in the garden under an outbuilding just because it would be pretty cool. I was going to dig down roughly 2.5-3metres pummel down hardcore into the mud then line it with a sheet or two. I would then build a tanking wall upto ground level using blocks on their sides. I was going to have a dwarf wall on the outbuilding above so that would be built on top of the tanking wall. My question is how to design the ceiling of the bunker/or floor of the outbuilding. Should I do a suspended concrete ceiling or block and beam. I would leave turrets (if thats the correct term) on top of the tanking wall so the beams can fit into place every 400mm or thereabouts.

Has anyone got any suggestions/advice? Thanks
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I suggest reinforced concrete shell; floor, walls and roof.

It's possible to build a basement with blocks, but the inward forces can be immense, so they have to be extremely thick.

You are permitted 30m2 floor area inside (excludes thickness of walls)

Damp will be a problem, and it will be cold.
I could put a french drain outside the blocks, hopefully that will relieve the weight of wet mud against the wall somewhat?...and loads of tanking slurry and bitchamen paint on outside. More tanking slurry on inside. Or would it be better to use 9inch hollows rebarred into the slab and filled? The building will be 5m x 3m so not overly big.

Top comment from the owner.

"it's wrapped in a waterproof membrane,, yes the walls are reinforced by steel and yes it is bone dry and has been since it was built. Just saying..." .. "less than £15k"

As the is not 2ft of soil on top its not good for radiation.

ICF concrete if you want to go all out. and i presume you've watched colinfurze on youtube?

And just for fun.
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The whole thing is just as a fun man cave tool storage project, nothing to do with the impending zombie attack . I want to build a shed on top with a dwarf stone wall but want to know how to go about doing the suspended ceiling which will be the floor of the shed.
Yes I've seen Colin furze. His bunker is mad and probably pretty costly. Thanks for the vids
Surely would be easier to bury a shipping container, if you have the access to get it craned in.
If we had a drier climate possibly but those containers rust quickly and don't have much strength.... plus condensation.

I might go with a block and beam floor instead laid across the tanking wall as I can't find much info on suspended ceiling pours
shipping containers are very strong down the legs and feet. The sides and top are just to keep the rain out. You sometimes see them dented. They will not withstand the weight on tons of earth piled on top, and static pressure from all directions.
Check uou havent got some mahoosive drain running across your garden, you dont want your mancave to become a giant inspection chamber......

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