Texas Tech's Wind Science and Engineering Research Center is probably a good place to look for information.

The usual problem guys run into with building a monolithic dome is the need to drive over to the wife's house to visit the family...

I don't see why an in-house shelter would cost $50k unless a lot of remodeling is done. The tricky part might be anchoring the shelter down in case a tornado throws a tree through the front door.

For the curious the website for David South's Monolithic Dome company is here.

I don't know anything about post-tension cable concrete slab construction, but this is a possibility if you can safely cut through the slab:

http://tswstormshelters.com/

Google "post-tension cable concrete construction" and you will find a ton of information.

Forget about cutting through a post-tensioned slab.

1) If you hit a cable someone could get seriously hurt.
2) When a cable gets cut your foundation is seriously compromised.
3) The only reason a post-tensioned foundation is installed is when the soil quality is bad.

As an architect I would suggest thinking of something else.

You might take a serious look at these...

http://www.familysafeshelters.com/existing.html


I have one and I have a friend that has one. Neither of us has tested them (Thank God) but they seem to be everything the manufacturer claims.

Standard disclaimers apply.

Hey, I like that! Do you have the 4x6 or 6x6?

-Blast

I got the "Beyond F5" model in a 4x8.

Blast,

There is a guy in Jerrell Texas doing the same thing. One of my previous homeowners did one after the fact. Not a bad idea at all.

Oh, I forgot to say. These things are like safes. Pick the size you think you need and then go up a size or two. I wish I had room for a bigger one.

Blast,

Don't give in to the dark side; build the Monolithic dome.

Standard Disclaimer

I'm just shocked, SHOCKED, that Blast said the word, "cut".

Cut?

tsk, tsk, tsk. Dear Sir, you need a nice Saturday afternoon, a six pack of PBR, five sticks of dynamite or modified shape charges, one bic lighter and large patch of backyard where you wish to put your new hole in the ground.