Does Putting Tornado Shelter in Garage Floor Compromise Slab? (how much, home)

[TGentry]

We are considering installing a tornado shelter in the ground below the garage floor slab. They will remove a section of the concrete and install it below ground.

Someone told me that this will compromise the post-tension support (or what-ever it is) of the slab. I mentioned that to one installation company rep, and he hemmed and hawed and finally said the way they do it, the slab will be fine.

Any thoughts? Thanks.

[MckinneyOwnr]

Depends on how it is done. If they cut the slab, but frame the opening with new rebar/concrete, it will be just as strong as it was previously.

If all they are doing is cutting the slab and digging a hole for the shelter and attaching it to the slab, that won't be as strong.

Just curious, how much did they quote you? I considered doing this before but have never pursued it at all.

[Rakin]

I would never do this. The odds of a super strong tornado in North TX hitting your home is about a Gazillion to 1.
There has not been a storm in the last 50 years here that would warrant this type of work.

Do you think the next Buyer of your home will be concerned about the damage to the foundation? I would be.

[f4shionablecha0s]

What's next? A meteorite shield? A fence around the property to keep the zombies out? A panic room in case a band of international terrorists descends from a helicopter to hold your family hostage?

The odds of getting hit with a tornado are so incredibly small... Think about it. How many times are you going to be killed in a car wreck on your way to work before you ever even see a tornado?

[Restrain]

The main slab should not be compromised. That being said, I would rather have it installed on the rear patio. Reason being, what will you do if you have just moments to get to a shelter, and your car is parked on top of the door?

[ChristieP]

Huge waste of money as others have said. This is not Kansas or Oklahoma.

[TGentry]

Hmmm. Some Interesting comments. preliminary research shows the cost to be 6000 dollars plus or minus.we are getting a grant that is good for the lesser of $3000 or 50% of the purchase price. So...for me, $3000 in out of pocket cost is worth the peace of mind. any other comments regarding the effect cutting into the slab will have on its integrity?

[ChristieP]

A grant? From the government? For a tornado shelter in a non-tornado prone area? Wow.

A better investment would be a reinforced "safe room" within your house. Since the odds of an F4-5 tornado in DFW are so small, at least the safe room would also give you protection from a home invasion. Statistically that's a lot more likely.

[f4shionablecha0s]

Originally Posted by TGentry

Hmmm. Some Interesting comments. preliminary research shows the cost to be 6000 dollars plus or minus.we are getting a grant that is good for the lesser of $3000 or 50% of the purchase price. So...for me, $3000 in out of pocket cost is worth the peace of mind. any other comments regarding the effect cutting into the slab will have on its integrity?

I don't think 6000 dollars is a realistic estimate for the kind of tornado shelter your envisioning. They're going to CUT THROUGH YOUR FOUNDATION. For 6000 dollars? Get real.

According to the website, there's also a huge waitlist and you can't start construction until after you're approved. Oh yeah, it can also take 12 months to get reimbursed.

I'm shocked that anyone would waste so much money on such a dumb project for an area that gets tornados so rarely. I'm SHOCKED that my tax money is going to reimburse the people who are doing so. There should be an investigation into this program...

[Rakin]

I would also talk to a real Foundation Engineer before I let anyone poke a hole in my slab.

What happens if adjustments or repairs are needed to the slab in the future?