Obviously, I'm going to have to seal the edges somehow so that no air can get beneath them.
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We used to have a tarp over our firewood. Two, sometimes three, cords. We were lucky in that cement blocks held the tarps down. Seems like you need one of the following:
1) Cinder Block - they sell cinder blocks without the holes in them. If you lay them edge to edge, without any spaces at all, they should hold your tarp/s down.
Having a little (very little) experience with this method, I would suggest you SINK an inch or two of the cinder blocks, as a strong wind will move them;
http://www.google.com/search?tbm=isch&source=hp&biw=1366&bih=654&ei=OkuaXZn2OZD5-gTwqbPYDg&q=picture+of+cinderblocks&oq=picture+of+cinderblocks&gs_l=img.3...5839.20235..22551...0.0..0.108.1670.22j1......0....1..gws-wiz-img.......0j0i10.alxr_BxMrDQ&ved=0ahUKEwiZ-7CzuYjlAhWQvJ4KHfDUDOsQ4dUDCAU&uact=5
2) 720 feet of edge: 720 feet, divided by 12 inches equals 60 cement blocks. Sometimes you can get cement blocks for $1.00 each, but not likely. You have to decide if this is the route you want to go.
DIRT FROM THE FOREST? You don't think this dirt is going to blow away? I do. They also sell dense cinder blocks, so no air can enter the tarp/s;
3) REBAR: did you think about rebar? Again, edge to edge, but it has to be thick enough to bury part of it.
http://www.google.com/search?tbm=isch&source=hp&biw=1366&bih=654&ei=vkqaXceYKIH--gT45pjYDg&q=picture+of+rebar+steel&oq=picture+of+rebar&gs_l=img.1.1.0j0i24.50892.57248..64133...0.0..0.94.1128.16......0....1..gws-wiz-img.gDKTS_M5zYo
The advantage of this, imo, is that you can roll it a couple of inches in the Spring, and back on the tarp in the Fall. I forget what the tarps are for, dammit.
This looks interesting: COCHRANE STEEL. They look wide enough to keep the tarps down, and easy enough to put them end to end.
http://www.google.com/search?tbm=isch&source=hp&biw=1366&bih=654&ei=vkqaXceYKIH--gT45pjYDg&q=picture+of+rebar+steel&oq=picture+of+rebar&gs_l=img.1.1.0j0i24.50892.57248..64133...0.0..0.94.1128.16......0....1..gws-wiz-img.gDKTS_M5zYo#imgrc=BFC1UxG1WFH55M:
4) This is my favorite and I think it will solve your problem:
How to Build a Backyard Hockey Rink
http://howtohockey.com/how-to-build-a-backyard-hockey-rink/
You only need WOOD. Inexpensive enough. You just need the proper tools.
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Where to buy Backyard Rink Supplies
Some of the most common supplies for a rink are brackets, boards, a liner and a handheld “Zamboni” to flood the ice. I have included two good resources below
EZ ICE RINKS – By far the easiest rink kit, a single person can build the rink with no tools in under an hour. If you use the EZ ICE RINKS promo code HOWTOHOCKEY you can save 10% and get free shipping
Iron Sleek – They’re a 1 stop shop whether you want to build your own rink and order their brackets and liner, or get a full kit. They just released their drop-in rink kit that is easy to assemble. Use the iron sleek coupon code COACHJ for 5% off and a free shovel!
HockeyShot.com Backyard rink kit – You get the brackets and liner for a 20ft x 40ft rink, you will need to purchase boards (plywood can be used). The rink can be expanded later with more brackets and boards and a bigger liner. Use our coupon code HOWHCKY001 for $10 off
Nicerink.com – You can buy everything you need.
Hey, go for the free shovel!
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If you're going the cinder block route, here are some ideas:
http://www.doityourself.com/stry/how-to-lay-cinder-block-with-adhesive
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You don't have to pay for cinder blocks. You can STEAL them. No, seriously, we got some of ours from builders in the area who had left-overs. If it's free, it's for me.
Hope this was somewhat helpful. Regardless, I would ask NEMO, as this is his area of expertise.
Have a nice Sunday!
If you think education is expensive, try ignorance.