I AM BUILDING A SMALL STORM SHELTER OUT OF PLYWOOD AND IT WILL BE BURIED IN THE GROUND.I NEED TO NOW WHAT I CAN USE TO WATERPROOF THE SHELTER WITH.

-- MICHAEL TODD FORD (TOD_33@EXCITE.COM), August 23, 2001

Answers

Hi Micheal, for the above ground part use Thompson's Water Seal, you paint it on, follow label directions. For the below ground part, use plastic roof cement, sold in hardware and lumber stores, paint on with an old brush that will not be able to be re-used. Let dry a day or two before you bury it under ground. Caulk all seams with a good quality acrylic latex caulk, again let dry thoroughly before putting underground.

-- Annie Miller in SE OH (annie@1st.net), August 23, 2001.

I would not use plywood for what you are doing. Why not start out with something that will not rot so easily. Do a search and find out what others are using and what works. I would pour concrete or use block. You could make it out of plywood and fiberglass it with a few layers, like making a boat (a lot of work). Good luck and tell us what you end up using.

-- ed (edfrhes@aol.com), August 24, 2001.

Michael-- in Mike Oehlers book "The $50 & Up Underground House, it tells you several cheap ways to waterproof underground walls. He does use plywood sometimes, and I've missplaced my copy but I think he even used tar paper attached to the outside of the plywood for waterproofing. Might try asking someone who has this book, I do remember he had several low cost ways to do this, and I guess it works. Wish I could help you more.

-- Trina in NE WA (dolittle@starband.net), August 24, 2001.

no matter how much you waterproof it, it won't last long unless you're in the desert or something. For a tornado storm shelter I'd want alot more than a sheet of plywood over my head.

-- Dave (something@somewhere.com), August 24, 2001.

Make it out of cement and you will only have to do it once. If you do use water sealer I would use CWF instead of Thompsons. I have a lot better luck with that on my deck, it lasts about 2 to 1.

-- Mel Kelly (melkelly@webtv.net), August 24, 2001.

You have never be able to waterprof a piece of plywood wood under the ground well enough to have it last any legnth of time. If you used large hardwood to build walls yes. Thats basicly the way older storm cellars were create but not with plywood.

How big of shelter do you need? You might want to check with a local farm supply store and see if they have any dammage 500-1000gall water tanks. Bury that instead. Concrete would also be a good solution but take a bit of work to build footers.

-- Gary (gws@redbird.net), August 24, 2001.

My handy dandy reference manual shows treated plywood with a visqueen moisture barrier, gravel surface trench, gravel perimeter footing trench with perforated drain tile. 4" concrete slab floor on top of another visqueen moisture barrier, on top of about 4" of sand. The visqueen moisture barrier appears to be six mil plastic membrane secured to the treated plywood with ashphalt adhesive.

cheers,

-- Max (Maxel@inwindsor.com), August 24, 2001.

Good Grief! If you are going to count on this shelter to save your life or that of your family, think cement or at least concrete blocks. Also, some of the shelters in Texas are buried metal tanks as mentioned above. Surf the net and get plans from your neck of the woods. Check with your local Co Extention Service, that's what we pay them for. Go to the library. Good luck. :)

-- Little Quacker (carouselxing@juno.com), August 24, 2001.

Do NOT use Thompson water seal, it will disolve the glue holding the wood together. I know from experience.

-- Rich (pntbeldyk@wirefire.com), August 24, 2001.