Flat storm shelters in the garage

[SwampSurvivor]

My relatives in Alabama had one installed in their garage. It's not large, but they can keep their medicines in it. They got it right after the 2011 Tornados went within a few miles of their house.

The one they bought is anchored through the garage foundation into the ground.

 

[Schmoe]

Good points....the one on using it to change oil had already crossed my mind. One thing about the debris issue....that's going to happen whether you have a flat safe or a partially above ground shelter. One thing that leaned me towards this particular style was when listening to one of the weather guys, none other than Gary Englang, when he said that unless your below ground, there isn't a lot of protection against a EF5 tornado. Also, if a direct hit, your house is not going to fall on top of the shelter, but rather be literally blown away with nothing left than a slab. Below that, you may lose your roof but a majority of the damage isn't going to fall on you. Plus, I also like the idea of having a car above the whole thing "just in case." I'm imaging an EF5, with cars being tossed around like match sticks slamming directly into one of those above ground shelters. Also, those doors are hinged. Imagine getting out there in high winds trying to shut one of those things.

 

[Mr_Incredible]

We have a cold room under our front steps. The door into it is in the lower level. Salt from the winter has buggered up the cinder blocks and we're going to have to replace it soon.

I thought we'd just get a concrete box put there instead of rebuilding it w/blocks. It would double as a shelter/root cellar.

Seems ok to me.

 

[Blaze]

I would build it inside the garage. It wont't effect the house. Slab on grade they usually dig deep footings anywhere a wall is located and that it what supports the structure...at least that's our we did ours. It also would serve as a nice pit for oil changes. Register the shelter with the city and you could also store something down there if you needed to cut yourself out but yep an EF-5 you shouldn't have a problem getting out.

 

[The_Jeff]

What gets me is the innocent grey color of that floor safe, I'd want some civil defense stickers etc saying "hey there's someone down here". Of course you can add your own graphics.

Do people leave supplies like a 5 gal joint compound bucket, with lid and TP, down there, in case the Oz they find above is scattered? Or is it the kinda place one spends 15 minutes in then climbs back out?

 

[Schmoe]

15-30 mins then out. Could also use it for aging homebrew.....my luck I'd forget to put in a bottle opener....

 

[Hokiefyd]

Originally Posted By: Schmoe
Just wondering about the effects on the overall foundation.


As others have stated, it won't affect the foundation of the house at all. Your garage is likely formed with at least three foundation walls (two sides and rear)...and likely either a full foundation or partial foundation across the front where the main door(s) is(are). The area between the foundation walls (the "slab" on which you park) is simply dirt fill with concrete poured on top that is X inches thick (usually something like 3-4 inches). You can excavate most of the slab area between the walls and not impact the foundations. The only caution would be that you wouldn't want to go too close to a foundation wall on either side (for stability while excavating). Most of these shelters I've seen are installed near the middle of the garage.

I would, however, share others' concerns about debris piling in a tornado. Obviously, if you take a direct hit from an EF5, there will be nothing left on your slab, and you can slide the door open and walk out. But the larger tornado threat...not in intensity but in probability...are the EF2s and EF3s. These will put a house down on its slab without necessarily removing it from its slab. Like this one for example:

That's from a CNN slideshow from the Moore, OK, storm. If you're in a shelter under that garage, you're still alive, but you're also not in a position to escape without significant assistance. From this viewpoint, a shelter in the yard may offer better escapability for the types of tornadoes you're most likely to face. GreeCguy also brought up the possibility of flooding...and that may be a real threat...either flooding from a water main or from heavy rain. Depending in where exactly your house is built and drainage around it, this may or may not be a concern to you. GreeCguy is right; that'd be a tough way to go.

 

[morris]

as a kid i spent some hours under the crawl under a reg house.

 

[Mystic]

A lot of houses still have crawl spaces underneath. If you do not have a shelter that would be one possibility. Better than nothing.

 

[Drew99GT]

Originally Posted By: PhillyJoe
We don't have storms like you do, but the thought of an underground shelter does not appeal to me for reasons stated above. If it was my house I would carve out a 6' by 8' or so first floor room or in the garage, cinder block on 4 sides, rebar down the cinder block and fill the holes with cement. Some kind of steel bracing for the ceiling, steel entry door. Tight quarters but it should still be standing even if the house isn't.


Even a safe room built like that will not stand up to the tornadoes Oklahoma has been getting lately. An EF-5 tornado will wipe steel reinforced concrete structure from the slab. From what I've read, shelters built into/under the garage slab are the most safe/economical. The absolute best is a dug out underground shelter that has a steel shell that is laid into concrete, but they are a bit on the expensive side.