Or how I spent my Father’s day in 2011. The family had already flown south for Vacation and I was to drive down a few days later with the dog and all the gear. Before I left I built a sandbox to surprise my daughter on her 5th birthday.
There isn’t much here but perhaps it will serve as inspiration for someone at some point. To give credit where credit is due, I pretty much aped this from an article posted by “This Old House: How To Build A Simple Sandbox”.
First up a chose a spot that is mostly shaded but does get some late afternoon sun to help dry things out. I decided to make the sand-pit a healthy 5×6 which based on my searches and resulting calculation would required about 1,500 lbs of sand. Any larger and the price of sand was going to make my head explode.
I chose to use pine 4x4s instead of cedar to save some money. The pine, especially the first course which is partially buried, will breakdown faster but based on the internet (I know…) my kids (5 and 0.5 at the time of construction) should be past playing in the sandbox by the time that happens. (Of course 1 year removed I wish I had spent the extra coin on the Cedar at least for the first course).
The only hard part here was digging out the 30 sqft plot, I dug down about 2-3 inches. Instead of the costly sand I used a bit of the freshly dug topsoil to lay a 1/2″ layer down around the edges as a bed for the first course of 4x4s. This helped with the leveling process. I didn’t join these boards in anyway.
I placed the second course down so that the 2nd course joints were not aligned with those of the first course. Hopefully you can see what I mean in the bottom right hand corner of the picture. The dog was quite upset once I put in the cloth and covered her nice cool soft soil with that scratchy sand…This past spring we put in an invisible fence so she now has full command of the yard, those rare times when she will suffer the indignity of leaving the house anyway. Prior to the invisible fence she would stay in the yard for about 10 minutes before darting across and down the street hence the 50′ leash she had to suffer in order to “help” on this project. 
I placed a 6″ deck screw (with the flattest/widest head I could find) every 14-18″ and in each corner. Here is the best tip I have for you in this post. After putting the screws in I scribed a line on the outside of the lumber, which you can see in the photo, to mark where each screw went. This way, when attaching the 3rd course I wouldn’t get any nasty surprises!
Before attaching the third course I put down a layer of landscaping cloth and draped it over the top of the 2nd course. Unfortunately I couldn’t get a roll that was wide enough (about 1-1.5 feet short) to do with one pass so I used two sheets at full width so as to maximize the overlap of the joint. The landscaping cloth will allow water to drain while keeping the sand in as well as prevent weeds from growing up into the sand. It will also prevent the sand from mixing with the soil below to make a muddy, clumpy mess. In short the landscaping cloth is a good idea! As the TOH site suggests I pushed the cloth into the corners and down the edges to ensure it was flat and not suspended. I also placed a good amount of sand down along the edges and in the corners as I went to ensure it stayed in place while I attached the final course.
The 3rd course goes in over the 2nd, again offsetting the joints at the corners and using the marks made along the sides to offset my 6″ deck screws. Before bolting down each of the four pieces of lumber I ensured that my landscaping cloth had enough slack so that it was not suspended above the ground in the corners and along the edge. After screwing the third course down I used a utility knife to trim all the excess landscape cloth from the outside edge.
3 trips to the big box store and 1,500lbs (yes I paid money for dirt) of play sand later and I am almost done.
The final step is to keep the cats, raccoon, skunks and all other types of varmits from using my sand-pit as the neighborhood rest area. For this I used some 1x2PT pine strips to make a frame and attached some PT latticework with some galvanized wood screws. I also tacked some landscaping cloth to the underside to keep pinestraw and other debris from falling into the sand. I made the cover in two pieces so the kids would be able to pull them off and put them back on (HA!!) without adult help. I didn’t feel the need to attach it. And so far through severe windstorms and feet of snow it has held up just fine.
Now all they need, so I am told, is a box into which their sand toys can be stored.