Underground Storage Problem

[okdkranch]

I could use some advice on converting a large deep underground storm shelter for prep storage. The problem is moisture. The one I have is about 10 foot deep (headroom inside), and quite large, not sure of the dimensions since I only went down there once when I bought my place. Constructed of reinforced poured concrete, buried on three sides in a hill. It has a steel lid in the roof which is 10 inches above ground with a nice lip and steel stairs to the bottom and two vents through the roof with now rusty gallon food cans over them. During the really wet times, the floor can get some standing water in it, maybe 3/8 inch deep or less, other times just moist. Oh, and there is no power out there and a fair distance from the house.
How can I stop the moisture to use this for food and other storage???

 

[angsniper]

Isn't there some sort of moisture barrier that you cover the walls with? Kinda like paint?

 

[Shoot Summ]

Two things, eliminate or reduce the source of moisture, and a method of removing it.

Think of it as a basement and all of the work typically involved. Sealing the outside of the walls, installing drainage systems to move the ground moisture away from the structure, etc. moisture removal could possibly accomplished with solar powered setup.

 

[OKC9-12LEDR1]

Two things, eliminate or reduce the source of moisture, and a method of removing it.

Think of it as a basement and all of the work typically involved. Sealing the outside of the walls, installing drainage systems to move the ground moisture away from the structure, etc. moisture removal could possibly accomplished with solar powered setup.

Sounds like the company that installed the room didn't consider the water table in your area, or didn't care. Shoot Summ is on the right track. It is going to require digging this thing back out. Not removing but digging around all sides. Seal it if you can clean the surface well enough. Dig down a foot or so below the base around the sides making a trench. Make a sand bed and lay down PVC French drain pipe, the kind with holes drilled down the length. Cover the pipe with weed fabric and fill the trench with course gravel. Put down another layer of weed fabric. Fill the area around the shelter with course gravel up to a foot or so from ground level. Another layer of weed fabric and put down your top soil. A foot of dirt will be enough to keep the grass on top alive and hold enough moisture for the grass.

If this is on a hill side as you said, you should be able to set the pipe on a grade and let the water run out on it's own. Worst case you might have to set up a sump pump in one corner and pump it out. That is where the solar powered sump pump would come in.

It's going to be a lot of work, but likely worth it if the room is big enough. Rent or borrow a backhoe for a weekend and dig it out.
Good luck.

 

[oldkar]

my house has a full basement, not a water leak since 1959. first coat the outside in a waterproof system. not a lot of call around here so home depot doesnt stock , but they will order it in for you, or try maxwell supply on n reno, 2nd french drains as above. install french drains inside under the floor, requires tearing out about 1 ft of concrete floor around inside perimeter and install a sump hole at lowest spot for a sump pit

 

[cowzrul]

http://concretesealers.com/basement.htm

You need a good vapor barrier. I installed one of those flat shelters in my garage when I built my house last year. We used half a truck of pea gravel as the base and installed a french drain around the shelter.

 

[SMS]

If it really gets standing water in it at times, I'd be inclined to say that it wouldn't be worth the work and money required to seal it up and make it suitable for serious, safe, long-term storage of food and other supplies.

The money you spend on that could be used for some creative, in-home, temperature controlled storage. Racks, organizers etc...

I'd clean it up, put some sealer on the inside walls, stock it with a small amount of supplies and use it for it's intended purpose as a short term tornado hidey-hole.

 

[Lurker66]

^^^^^^This is the right answer. Just use it as your hidey hole during a tornado.

 

[Hannibal7]

I would have to agree with these latter comments. You definitely could make it a dry environment with enough work, but in terms of the allocation of your time and money, you'd come out better by just de-purposing it from prepping storage.

 

[EFsDad]

Damn it guys! I have the same situation except I get a foot of standing water when the springs are running. Not that we have had to worry about it the last 3 years, but I was hoping to hear the magical solution to waterproofing a scardy hole. We will be in there during a storm water be damned, but was hoping for some type of climate controlled storage.