im lookn 4 sum specs & safety precautions 2 manually dig a safe underground room?

Question

I want to dig an underground room, but I'm having difficulties finding good info on how deep to go for the ceiling not to cave in and other safety precautions. Everything I've found has been pretty vague, which makes me a bit leery to attempt the venture underground. Somebody please help a hermit that just wants some "tranquility with nature!"

Answer 1

Assuming that you are building a Tornado bunker or a root cellar, a good rule of thumb would be to dig at least halfway under the deepest frost/freeze line. Potentially up to 12' +/- in depth. I would recommend framing this structure with pressure treated 6x6's and leave enough room to deck the top of the frame with 3/4" plywood to help disperse the ground pressure evenly. Under the framing I would use some type of stone or masonry footings to prevent rot and avoid the frame work from being driven into the ground. Good luck.