For backyard play equipment a sandbox is good place to start! Children can have hours of fun in a sandbox using their imaginations, building castles, towns or cites. Some great The plans for this sandbox are very simple. The box itself can be built in a morning (except perhaps hauling in all the sand!) and is very inexpensive. The size of this one is good and the depth is quite adequate for digging. The bottom is left completely open which will insure any water drains out, and offers you the opportunity to dig out even more under the sandbox to allow even deeper digging (for the really deep excavating children!). I think the sand in the center of mine is about 2 ft deep and the kids almost never hit dirt! Also since I dug out the area, I was able to place the sandbox in the hole, this made the sides only about 6 inches above grade to allow for easy entry for the little ones.
The approximate cost of this project is $60 for the materials (excluding the cover). The sand... well if you buy it by the bag it is about $100. If you have a pickup (or a friend with one) and buy a ton of sand, it costs about $8 for a ton. (In fact where I got it, they will give it to you for free if it is for a sandbox!) A ton of sand is about what you need for a sandbox of this size.
A cover for the sandbox is probably a necessity since cats will almost surely find your wonderful new litter box. I have used a variety of covers for mine. The important thing is it needs to be light enough for the kids to lift, and simple enough for them to re-close, or like I have done, you will have to sift out what the cats leave behind. (Not fun!) Unfortunately, I have yet to uncover the optimal sandbox cover. I tried a tarp with snaps, but it didn't last, the snaps which should have been stainless steel, weren't...! The tarp ripped anyway. I was amazed to see the cats wiggling their way in and out of the smallest gaps left unsnapped, and the kids rarely covered it right on their own.
So, I built folding doors. These got quite complicated, they are bifolds and to make them light I used pressure treated lattice panels inside the frames. Well the supposedly brass hinges, weren't, and they rusted away. The new ones cost a fortune (they are solid brass) and the screws that hold them keep stripping out and I have used progressively longer screws. And the lattice took a beating. You see the kids walked on it, and it isn't that strong. Now, my panels are a combination of chicken wire and lattice and I am glad the kids are growing up and the sandbox is about to be returned to lawn because those doors are about shot. Still the doors DID last about 10 years.
I am going to take the easy way out and tell you to buy stainless steel snaps and a good tarp and wish you luck. (I've seen them sold this way) If you think you can handle the bifold door idea, you are on your own. And if you come up with a better idea, PLEASE let me know.
Saw (circular saw is best, a hand saw will work just fine, there is not a lot of cutting)
Drill: With the following drill bits:
1/4" spade bit (long enough to drill 5 inches)
1/8" drill bit to predrill screw holes
3/4" spade bit for countersink holes
1/2 socket wrench
This sandbox is built using 2x12's
All wood should be pressure treated unless otherwise noted
All Hardware should be galvanized unless otherwise noted
The sandbox is 6 ft. by 6 ft. Two 12 ft long 2x12's can be purchased and each cut in half
to provide the boards for the sides. Or buy four 8-ft boards and cut them to 6 ft long. The sides are joined at the corners with a corner post. Which is bolted to each of the boards at the corner.
For the corner post use a 2x4 cut 1 ft long and attach the sides to the corner post with 1/4 inch carriage bolts. The 2x12s can be nailed together first with 16-penny nails first to hold it all together before adding the corner posts. The sides should be secured with 6 carriage bolts per corner. The length of the bolts specified ensures they will no protrude through the wood. This will keep them from catching anybody in the back.
Nail the four side boards together. Then holding corner posts in place, drill the holes for the carriage bolts. First drill the ¾" countersink holes ½ inch deep in the corner post, then drill the ¼ inch diameter holes all the way through the post and the side boards starting inside the center of the countersink hole.
Install the bolts from the outside, that is through the side boards going in to the post. You will probably have to hammer them through. Install the washer and nut and tighten down firmly with a socket wrench.
OPTIONAL: The size can be made smaller (or bigger!) if you wish, just reduce the dimensions accordingly.
Description of how to build the corner seats:
The seats can be made from pressure treated 1/2 in plywood or better, from 1x4's.
Plywood: Cut a 1-ft wide strip off the plywood on the 4-ft length of the plywood. Cut it into 4 triangles with 1-ft sides.
Attach these to the corners using 1-1/4 in exterior wood screws
1x4's: Cut four corner pieces. These will be triangles made by cutting the board in two 450 angles. Attach these to the corners with four 1 1/2 in exterior wood screws. (Predrilling the holes in the 1x4 material will prevent the small boards from splitting. And cut four pieces 1ft 6 inches and secure these next to the corner pieces with 4 screws each. Trim the boards to fit flush with the sides.
Bill of Materials
2 2x12's 12 feet long. Sides
1 2x4 8 feet long Corner Posts
1 4x8 sheet of pressure treated plywood or half sheet 4x4 if available seats (Optional if making seats with plywood)
1 1x4 8 feet long seats (Optional if making seats with 1x4's)