Integrating Above-Grade Storm Shelter
We are working through the design of a house, and one of the things we have been toying back and forth with is the need for a basement. Space for a mechanical room is one aspect, but that can easily be fairly accommodated for above grade. The other concern is primarily tornado safety. Michigan isn’t exactly tornado alley, but we do get a yearly warning it seems. We have historically gone into the basement for this, which isn’t an ideal tornado shelter, but it’s something. One thought was to create the walk-in closet as a wood frame storm shelter. Currently our plan shows this in the corner of the house with a window, door to the bedroom and pocket door to the laundry room. Doors would need to be steel and the window would have to go or add steel roller shutters to the outside.
I am curious what other slab on grade builders have done for a storm shelter?
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Tim_O,
I'd be tempted to use a pre-fab one. I think even HD sells them.
They do, $4000 for a small one. Couple thousand more gets you a little extra space. Just have to find the floor space, I think the prefab metal ones are a little tougher to dual purpose as something else. I think there are models that fit under stairs even.
Tim_O
It's not something I've thought much about, but I wonder whether it makes more sense to anchor a largely separate room (either pre-fab or site built) to the slab, which would survive independent of the rest of the structure, as opposed to beefing up part of the framing and integrating the room more closely with the rest of the house?
Yeah, I think that probably is the easiest route. They aren't huge, so it doesn't need much space. Heck, it probably could be in an attached garage even.
One option I've seen is to excavate an area under the concrete slab in the garage and install a steel tornado shelter. There's a sliding door in the floor of the garage with a set of steps going down into the shelter. Seems like it would be very safe since it's completely underground and it doesn't take up room in your house. Also doesn't affect the storage area of your garage.
If you prefer to go the route of building a safe room in your house, do a Google search on "FEMA - Taking Shelter from the Storm - Building or Installing a Safe Room for Your Home, FEMA P-320". It contains tons of information about building storm shelters, including detailed drawings for different foundation types, rebar layouts, door design, etc... If you want to construct an above ground shelter, it shows how you can use 2 layers of 3/4" ply and 1 layer of 14 gauge steel as your wall sheathing - also specifies the nail size and nailing pattern. It's very thorough. Worth a look if you're serious about building a shelter.
Yep, they have an excellent set of instructions. I believe this is the method used to make a closet or other into a storm shelter.
Unrelated to your post but I am also in Detroit. Shoot me an email [email protected]. would love to see what you're working on.