How to Build a Wall Box Shelf

Cut a 45-degree angle on the 6-inch ends of the 3/4-by-6-by-16-inch plywood panels with a miter saw. One side still measures 16 inches long, and the opposite side will be shorter on each panel. In other words, the long points will be on the same side. Repeat this process on the two 3/4-by-6-by-36-inch plywood panels for the 6-inch ends. This will allow the two sets of panels to fit together like a picture frame to form a box.

Place the 3/4-by-6-by-36-inch plywood panels parallel to each other with the 3/4-by-36-inch edges flush against a work surface. Orient the panels horizontally. Place the 3/4-by-6-by-16-inch panels on the ends of these panels to form a rectangular assembly.

Apply wood glue to the ends of the panels where they join together. Press the assembly together, and clamp it for 24 hours with a frame clamp. Wipe off the excess glue with a damp rag. Remove the clamp.

Center the 1/2-by-16-by-36-inch plywood panel over the top of the assembly. This is the back board of the wall box shelf. Hammer finish nails every 4 to 6 inches through the back panel into the box assembly to fasten it in place.

Brush a coat of wood finish onto the completed wall box shelf assembly with a paintbrush. Allow the first coat to dry for 4 hours, and then apply a second coat. Wait 24 hours before handing the shelf assembly.

Select a location on the wall for the box shelf. Slide a stud finder along the wall, and mark the location of the wall studs nearest the selected location with a pencil. Center the shelf assembly against the wall over the pencil marks. Drive two evenly-spaced wood screws through the back of the assembly into each wall stud location with a screw gun.