Hello all, I am considering building an ICF "tornado shelter" in my basement. I want to add it into the corner where two 9ft concrete walls come together. Any thoughts or considerations as to the best ICF product to use for ease of construction (to include a ceiling) would be great. I have a briefly read through the FEMA plans for shelters but did not see enough detail on this subject for my circumstances. Has any one on the forum done this before? As an aside the home is 10 yrs old. If I have left out any details you need please let me know. Thanks.

Why not use concrete blocks and then form a poured concrete cap with wood forms?

I did have that thought but, couldn't come up with a sound way of attaching it to the existing concrete wall. I want to rebar the new concrete to the old concrete. Not just at the floor but, the walls too. Any thoughts ???

Be sure to swing the reinforced door into the storm shelter unless you keep a well-running chain saw there.

If there is headroom, then either a metal pan or an ICF product like Lite-Deck or Insul-deck could be used as the form for the ceiling.  ICF roof forms should be be monolithic with the wall forms.  Bent rebar from the wall into the ceiling's concrete will hold the top on.  Depending upon the size of the storm shelter, shoring may be needed to support the top for 28 days until the concrete cures enough.

> I want to rebar the new concrete to the old concrete.

Drill holes and epoxy the rebar in. Then extend it into the joints between blocks and into the cores.

Build a steel box it will be more easy and cheap.

Thanks for the input so far. Good points to consider. Keep them coming. I downloaded the FEMA specs and will be back on if I can think of any further questions. Thanks for the help so far. I will post pics/ vid before, during, and after the room is complete.

Well, this humble fellow reportedly designed and is building his entire “green” 75,000 SF residence using TF Systems ICF and Helix steel fiber to be EF5 tornado resistant:

http://en.wikipedia.org/wiki/Pensmore

http://www.tfsystem.com/Benefits/DisasterResistance.aspx

http://helixsteel.drupalgardens.com/projects/icf/pensmore

I think TF is full of baloney. That link says you can use TF for military buildings but TF don't meet the Army corps of engineers spec for icf construction. I ran into this once before.

What exactly is the Army Corps of Engineers ICF spec? We don’t have anything against the Corps, but their specs and practices have resulted in some of our worst man-made national disasters. I would agree that some of the TF claims seem far-fetched. I would like to see Pensmore actually completed (seems like a never-ending project) and then hit by a EF5…

Unified Facilities Guide Specification 03 11 19.00 10 February 2012