Lumber and Plywood Storage Cart

Screw the base together with 2-1/2" screws (or pocket holes at a 1-1/2" setting with 2-1/2" pocket hole screws), checking for square. Add the caster wheels at this stage — waiting until later makes wheel access awkward.

Build the wall frames, then attach them to the top of the floor framing. You'll need to screw at an angle to attach the wall verticals into the floor studs.

Place the plywood floor panels between the walls and screw down with 1-1/2" screws.

Add cross bracing to keep the walls square, screwing on with 1-1/2" screws.

For additional support and storage of smaller plywood pieces, screw 1x4 trim around the top panel.

Cut the four side/divider pieces with an angled top from a strip of plywood, all identical. Attach a front and back piece across the strips, then add dividers between them as desired.