Apply wood stain and varnish to the various beams with a paintbrush if you can’t find pre-treated lumber.
Use a measuring tape to measure the dimensions of the firewood rack space you have available to build a 4-foot by 6-foot rack.
Cut the width and length of the beams to build a 4-foot by 6-foot rectangle rack frame. Nail the cut beams together with nails and a hammer to make the base of your wood rack. Once constructed, reinforce the rectangle at the corners by inserting wood screws with a power drill.
Place an upright beam 5 feet tall at each corner. Use wood screws to attach it flat to the long-side base beams in the rectangle, tucked into the four corners. Use the table saw to cut four pieces of 2-inch by 4-inch beam wood to a length of 1 foot each. Cut the edges again at a 45-degree angle so it forms a diagonal brace beam. Place the small pieces against each vertical beam to act as a brace. Use wood screws to attach the small pieces to the base frame and beams.
Build a 4-foot by 6-foot top rectangle to complete the firewood rack frame using the 2-inch by 4-inch beams. Drill holes in the upper rectangle after lining it up horizontally with the top of the vertical beams. Bolt the rectangle frame to the top of the vertical beams via the holes and nuts and bolts. Tighten the hardware with crescent wrenches.
Use the table saw to cut a plywood sheet to a measurement of 4 feet by 6 feet in size. Place the cut flat panel over the top of the 4-foot by 6-foot frame. Nail it to the top of the rectangle base to keep it from moving or blowing off. Cut a second panel using the same sizing as the top lid. Turn the rack over on its top. Nail the second sheet to the bottom of the rack. Turn the construction right-side up again once the bottom platform is installed.
Load up the new rack with firewood once it is moved into place where it will sit.