In my basement I am wanting to put a storm shelter. It is a 4″ concrete slab, and under that is plastic underlayment and about 4 to 6″ of stone. The ground underneath is pretty much solid sandstone. I was wondering if I could put a concrete block wall on top of the slab, if I would need to drill holes and drive in rebar, or if I would need to cut the concrete, dig out and pour other footers? The edges of the slab rest on about 3 to 4″ of the footer. I am only wanting a 7′ wall with a metal or concrete roof on it. Any help would be appreciated. I have not seen any evidence of settling problems in the basement.
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story

Listeners write in about removing masonry chimneys and ask about blocked ridge vents, deal-breakers with fixer-uppers, and flashing ledgers that are spaced from the wall.
Featured Video
Video: Build a Fireplace, Brick by BrickHighlights
Fine Homebuilding Magazine
- Home Group
- Antique Trader
- Arts & Crafts Homes
- Bank Note Reporter
- Cabin Life
- Cuisine at Home
- Fine Gardening
- Fine Woodworking
- Green Building Advisor
- Garden Gate
- Horticulture
- Keep Craft Alive
- Log Home Living
- Military Trader/Vehicles
- Numismatic News
- Numismaster
- Old Cars Weekly
- Old House Journal
- Period Homes
- Popular Woodworking
- Script
- ShopNotes
- Sports Collectors Digest
- Threads
- Timber Home Living
- Traditional Building
- Woodsmith
- World Coin News
- Writer's Digest
Replies
I'm assuming a tornado shelter? A 4" Slab is just not enough to anchor anything substantial to. I would cut the slab and pour a footing (depending on the size of your shelter a thickened pad for the shelter might be the easiest way). I would build the walls like a concrete retaining wall. Also I would pour concrete instead of block. The block needs to be grouted anyway, so just build forms and pour concrete. I started construction building forms so I am likely biased in that regard. Good luck.
In general I agree with Greg, but given what your trying to accomplish, talk to a structural engineer. If I was sitting in the shelter, I would want to know I did everything I could to protect my loved ones sitting next to me, while the world is trying to destroy me.