Build a Timberframe Sandbox

How to Build a Timberframe Sandbox

1. 1 Prepare the Site

   

   Outline a 48 × 96" area using stakes and strings. Use a shovel to remove all of the grass inside the area. Dig a flat trench that’s 2" deep × 4" wide around the perimeter of the area, just inside the stakes and string. 

2. 2 Prepare the Base

   

   Place the first tier of sides and ends in the trench so the corners on successive rows will lap over one another. Place a level across a corner, then add or remove soil to level it. Level the other three corners the same way. Drill two 3⁄16" pilot holes through the timber sides, then drive 6" barn nails through the pilot holes.
   
   Measuring from the inside of one end, mark for the inside edge of the storage box at 18" on both sides. Align the storage box wall with the marks, making sure the corners are square, and then score the soil on either side of it. Remove the timber and dig a 3" deep trench at the score marks.
   
   Replace the storage box timber in the trench. Its top edge must be 3⁄4" lower than the top edge of the first tier of the sandbox wall. Add or remove dirt until the storage box timber is at the proper height. Drill 3⁄16"-dia. pilot holes through the sandbox sides into the ends of the storage box timber, then drive 6" barn nails through the pilot holes.
   
   Pour 2" of coarse gravel into the sandbox section. Cover the gravel bed section with heavy-duty plastic sheathing. Pierce the plastic with an awl or screwdriver at 12" intervals for drainage.

3. 3 Build the Sandbox Frame

   

   Set the second tier of timbers in place over the first tier and over the plastic sheathing. Starting at the ends of the timbers, drill 3⁄16"-dia. pilot holes every 24", then drive 6" galvanized barn nails through the pilot holes.
   
   Stack the remaining storage box timbers over the first one. Drill 3⁄16"-dia. pilot holes through the sandbox sides into the ends of the storage box timbers, and then drive 6" barn nails into the pilot holes.

4. 4 Build Storage Box Floor + Lid

   

   Cut the floor cleats and position one against each side wall along the bottom of the storage box. Attach them using 2" galvanized screws. Cut the floorboards and place them over the cleats with 1⁄2" gaps between boards to allow for drainage. Fasten the floorboards to the cleats using 2" screws.
   
   Cut the lid boards and lay them out side-by-side, with the ends flush. Cut the lid cleats and place across the lid, one at each end and one in the middle, making sure the end of each cleat is flush with the back edge of the lid. Drill pilot holes and attach the cleats using 2" galvanized screws.
   
   Attach the lid to the sandbox frame using heavy-duty child-safe friction hinges.

5. 5 Build Corner Benches

   

   Cut the bench cleats. Mark 3⁄4" down from the top edge of the sandbox at two corners. Align the top edges of the bench cleats with the marks and fasten them using 2" deck screws.
   
   Cut the corner bench boards to length with a 45° angle at each end. Place it in the corner and attach it to the cleats using 2" screws. Cut the bench boards to length with a 45° angle at each end. Butt it against the corner bench board, and then attach it to the cleats.
   
   Repeat this step to install the second corner bench.

6. 6 Fill Sandbox + Install Border

   

   Mark an area the width of your pavers around the perimeter of the sandbox. Remove the grass and soil in the paver area to the depth of your pavers, plus another 2", using a spade. Spread a 2" layer of sand into the paver trench. Smooth the sand level using a flat board. Place the pavers on top of the sand base, beginning at a corner of the sandbox.
   
   Use a level or a straightedge to make sure the pavers are even and flush with the surrounding soil. If necessary, add or remove sand to level the pavers. Set the pavers in the sand by tapping them with a rubber mallet.